TX 

38? 



Issued Scptombcr 5, 1!)0S. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF CHEMISTRY— BULLETIN No. 114. 

H- W. WILEY, Cliirf c.f Buroan. 



MEAT EXTRACTS AND SIMILAR 
PREPARATIONS, 

INCLUDING STUDIES OF THE :\1ETH0DS 
OF ANALYSIS EMPLOYED. 



]'.Y 



W. "D. P.IGELOW, 

CHIEF, DIVISION OV FOODS, 

AND 
Y. ('. COOK, 

!'I[VSIOI.O(;lCAL (TIK.MIST. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

19 8. 




Book - U .-Tf 



V -^ 



Issued September 5, 3 DOS. 

U. S. DEPARTMENT OI' AGRICULTURE. 

BUREAU OF CHEMISTRY BULLETIN No. 114. 



ir \V. WILKV. (Iiiif ..f lliinuli. 



MEAT EXTRACTR AND SIMIIAR 
PREPARATIONS, 

INCLUDING STUDIES OF TUK METHODS 
OF ANALYSIS EMPEOYED. 



BY 
W. 1). J'.IGELOW, 

CHIEF, IllVISIOX OI' FOODS, 

AND 
F. C. COOK, 

PHYSIOUXilCAL CIIEiMIST. 




WASHINGTON: 

GOVERNMKNT TKIXTINt! OFFICE. 



1 y () 8 . 



■J 



i> 






SE?14»908 



1? 



LEITER Ol^" TRANSMITTAL. 



U. S. Department of AciKiciTr.TiTRE, 

Bureau ov Chemistry, 
Wai:hlngton, D. ('., October W, l!H)7. 
Sir: I have llic lioiKir to transmit lierovvith the results of a chciii- 
ical study of various preparations made from meat, anil some sub- 
stances used to adulterate such products. In addition, conunents 
on the nutritive value of meat extracts and similar products have 
been compiled from the literature of the subject. The wide use of 
preparations of this nature by invalids and others seekin<j; a con- 
centrated nutritious food rather than a stimulant, and the fact that 
but little is generally known of the actual composition of these prod- 
ucts, make it advisable to publish the information ol)taincd in the 
course of these studies, wliich were primarily conducted for the estab- 
lishment of standards. 

I recommend that this manuscript be pulilished as Bidlctin 114 of 
the Bureau of Chemistry. 

Respectfully, H. W. Wiley, 

Chief of Buiraa. 
Hon. James Wilson, 

Secrrtan/ <f Agriculture. 

3 



CONTENTS. 



Page. 

Chemical examination 7 

Objects of tlie investigation 7 

Description of samples 7 

Comment by manufacturers 8 

Meat extracts 12 

Tentative standards 12 

Methods of preparation 13 

Solid meat extracts 14 

Fluid meat extracts 15 

Meat juices 18 

Tentative standard 18 

Discussion of results 18 

Yeast extracts 20 

Manufacture and use of yeast preparations 20 

Methods of detection 21 

Result of tests 21 

Miscellaneous preparations 24 

Classification 24 

Discussion of results 25 

Methods of analysis and their discussion 28 

Preparation of sample 28 

MoLsture 28 

Ash 28 

Separation of organic and inorganic phosphorus 31 

Acidity 31 

Nitrogenous bodies 32 

Classes of nitrogenous constituents and general methods of separation . . 32 

Insoluble and coagulable proteids 33 

Proteoses and peptones 34 

Gelatin 35 

General discussion ., 35 

Experimental work on methods 36 

Total meat bases 38 

Kreatin and kreatinin 39 

Application of kreatinin test to meat extracts 39 

Application of kreatinin test to tannin-salt filtrate 40 

Xanthin bases 40 

Ammonia 41 

Succinic acid 41 

Ether extract 42 

Glycerol 42 

Nitrates 43 

Undetermined matter 44 

Historical note on nutritive values 44 

Gelatin 44 

Meat extracts and juices 48 

Cond usion 54 

5 



MEAT EXTRACTS AND SIMILAR PREPARATIONS, IN- 
CLUDING STUDIES OF THE METHODS OF ANALYSIS 
EMPLOYED. 



CHEMICAL EXAMINATION. 
OBJECTS OF THE INVESTIGATION. 

For several years past the Division of Foods of the Bureau of 
Cheinistrv has examined many of the meat extracts and so-caOed 
meat juices. During the winter of 1905-G a complete analysis of 
more than thirty meat preparations was made. While the work 
was in progress, several questions were raised which demanded 
further study and consequently delayed the publication of the results. 

The object of the investigation was to determine the condition 
and quality of meat prcj)arations, many of which are widely adver- 
tised and highly recommendeil for invalids. The need of standards 
for judging the merits of such preparations is evident, and the fact 
that complete analyses of American meat jireparations are not 
available makes the publication of the results obtained desirable. 
The tentative standards for meat extracts and meat juices, peptones, 
and gelatm, as prepared 1)V the Committee on Food Standards of 
the Association of Official Agricultural Chemists, are given luider the 
appropriate captions. 

DESCKIPTION OF SAMPLES. 

The samples which were analyzed in this investigation were pur- 
chased on the retail market in the winter of 190.5-6 and represent the 
market conditions ]irior to the passage of the meat-inspection act by 
Congress June .'lO, 1900, and the enforcement of the same by the 
Bureau of Animal Industry. It is well known that products of this 
class vary somewhat from ycai' to year, and, moreover, tlifl'erent 
results may be obtained on the same sample l)y the application of 
ditTerent methods. As the same treatment was given to all of the 
preparations included in this report tiieir relative values are fairly 
indicated. In connection with the descriptive tal)le are given such 
comments as the manufacturers or agents of the various pre]>ara- 
tioiis otfered when the analyses were submitted to them. 

7 



MEAT EXTEACTS. 
Table I. — Description of saniplrs analyzed. 

SOLID MEAT EXTRAfT-CSEK TABLE II). 



Serial 
num- 
ber. 


Name of preparation. 


Manufacturer. 


15867 
15868 

15869 


"Rex" Brand Beef Extract 

Liebig's Extract of Meat 


The Cudahy Packing Company, Omaha, Nelir. 
Liebig's Extract of Miiit Company, .\nt\verp. Belgium. 

(Agents, CorneillH, Huvid & Co., 120 Hudson street, 

New York, N. Y.) 


16048 




Libby, McNeill and Libbv, Chicago, 111. 

Swift" and Company, Chicago, III. 

G. II. Ilanmiond Company, Chicago, 111. 


16049 
1(1060 


Beef Extract 







I'LUID MEAT EXTRACTS— (SEE TABLE IV). 



15964 
15965 


Concentrated Fluid Beel Extract 


Armour and Company, Chicago, 111. 
John Wyeth and Brother. Philadelphia, Pa. 
Valentine's Meat .luief Cnnii)any. Richmond, Va. 
Armour and Company, riiieago. 111. 
The Cndahv I'aekiuK C"iupaiiv, Omaha, Nebr. 
Cibils Companv. Iniportrrs, Nrw York, N. Y. 
The .\I..squira .luliu Food Company, Detroit. Mich. 
(Agents, Parke, Uavis A: Co.) 


15966 


Meilt Juice.. 


15977 
1.5979 


Vigoral 

*■ Rex" Fluid Bex-f Extract 


15990 
15991 


Fluid Extract of Beef 

Fluid Beef Jelly 



MISCELLANEOUS PREPARATIONS— (SEE TABLE IX). 



15911 
15903 



15976 
16040 



Bouillon Capsules 

Bovril, Seasoned 

Beef Jelly, Mosquora Extract of Boef. 

Essence of Beef 



16044 Predigested Beef 

15870 Soluble Beef 

15908 ' Bovox Essence of Beef. 

15909 Johnson's Fluid Beef. 



15988 
159S9 



16043 
15978 



15910 
16037 



16039 
16041 



American Brand Extract of Beef 

Bovinine Concentrated Beef 

Essence of Mutton 

Liquid Food (extnictof l)eef, mutton, 

and fruits). 
Maggi's Bouillon 

Peptonized Beef. Rose 

Beef Extract and Vegetal)le Tablets. 
Leube-Roscnthal's Beef Solution 

Malted Meat Extract of Beef 

Beef Peptonoids 



Royal Specialty Company, New York, N. Y. 

Bovril (Ltd.), "London, England. (Park and Tilford, 

agents, New York, N. Y.) 
The Mosquera-Julia Food Company, Detroit, Mich. 

(Agents, Parke. Davis & Co.) 
Brand and Company (Ltd.). Mayfair, Vauxhall, S. Vi. 

London. (Fougera Company, agents, New York 

N. Y.) 
H. K. Mulford Company. Philadelphia, Pa. 
Armour and Company. Chicago. III. 
The Bovox Company, Boston. Mass. 
Bovril (Ltd.). Montreal. Canada. 
American Beef E.xtract Company. Boston. Mass. 
The Bovinine Company, 75 W. Houston street, New 

York. 
The London Essence Company, London, England. 

(W. B. Hard and Company, IS Cedar street. New 

York, N. Y.) 
Murdock Liquid Food Company, Boston, Mass. 

The Maggi Company, Kempttal, Switzerland. (J. P. 

Smith and Company, agents, 90 Hudson street. New 

York, N. Y.) 
P. B. Rose. {General agents. Chapman, Green and 

Company, Chicago, 111.) 
Armour and Company, Chicago, III. 
Ph. Rndisch. (Cheppe and Schur. agents, Third avenue 

and 60th street. New York, N. Y.) 
American Malted Meat Company, South Milwaukee, 

Wis. 
The Arlington Chemical Company, Yonkers, N. Y. 



COMMENT BY MANUFACTURERS. 



The analyses of the commercial pnxhicts examined were referred 
to the manufacturers or their agents, ami the following extracts from 
the replies received are submitted. 

The letters addressed to the American Beef Extract Company, 
Boston, Mass.; American Malted Meat Company, South Mihvaukee, 
Wis.; Cibils Company, New York City; W. B. Hurd and Company, IS 
Cedar street, New York City, and to Chapman, Green and Company, 
Chicago, 111,, were returned unclaimed. The following manufacturers 



COMMENT BY MANUFACTURERS. 9 

replied, but ofl'ered no oriticisni of tlie analyses: Tiie Bovinine Com- 
pany, 75 West Houston street. New York City; the Muidock Li(|ui(l 
Food Company, Boston, Mass.; Fougera and Company, 00 Beeknian 
street, New York City, and the Liebig's Extract of Meat Company. 
From the following manufacturers no reply was received: 
Swift and Company, Chicago, 111.; G. II. Hammond Company-, 
Chicago, 111.; Cibils Company, New York City; Royalty Specialty 
Company, New York City; The Bovox Company, Bost<m, Mass. ; Tiie 
London Essence Company (W. B. Ilurd and Company), IS Cedar 
street. New York City; Ph. Rudisch (Cheppe and Schur, agents), 
Third avenue and Sixtieth street. New York; American Malted Meat 
Companj', South Milwaukee, Wis. 

. The Arlincton ('iiemical Company. 

No. I«)41. 

The analysi.s suljmitted ))y ydu evidently refers to the preparation, Beef Peptonoids 
Powder, formerly manufaetured l)y vis, but whieh was superseded June 1, inOli, l)yan 
entirely different form, under the name of Dry Peptonoids (.Soluble). This was done 
after several yeans' experimentation demonstrated that we could inerea.se the nutrient 
value, improve the taste, and render the powder entirely solvil)le. The old form, Beef 
Peptonoids Powder, has been taken off the market and all stork in hands of the trade 
taken up. 

Therefore we believe that the publication of an analysis of this oljsolete preparation 
can be of no possilile interest to anyone, and that the com]H)sition of the form now in 
use and on the market should l>e determined and i)ul)lished l)y you. » » * 

We believe, in view of the facts as given herewith, that in justice to us. and ini>rder 
that the object of the Bureau of Chemistiy be aic-oiii]i!ishcd. an analysis of the Dry 
Peptonoids (Soluble) should be made by you and puldi.shed in accordance with the 
provisions of the act of Ccmgress cited in your letter. 

[In accordance with the retpiest of The Arlington Chemical Com- 
pany, the following analysis of the "Dry Peptonoids (Solul)le)," as 
made by their chemist, December 1.5, 190G, is given in this connection:] 

Pit (int. 

M( listiu'e 5. () 

Nitrogenous compounds (N x G.2.5) :ffl. 5 

Total carbohydrates, after inversion -Jli. 7 

Ether extract (fats and lipoids) 0. :} 

Mineral constituents (ash) 5.8 

Insoluble material 1.0 

Comment ty autJiors. — The writer was informed that as the entire 
report represented the samples on the market in the winter of 190.5-6 
it would not be just to other manufacturers to bring the work up to 
date in one case alone. 

Armour and Company. 

N09. 15869, 15870, 15910, 13904, luul l.Wi;7. 

The results are very different from what we should expect, anil from results whicli 
we have oljtained in our experience with these products. 

The most striking feature is the low results you report on kreatin and krcaliiiin. As 
a mailer of fact We find that it makes a gri-at difference wliicb aielhod is iisnl in deter- 



10 MEAT EXTRACTS. 

mining total kreatinin. The motliod we use in tliis lalioratory is the modification of 
Folin's method as suggested l)y Gi'indley and Woods. From our experience we pre- 
sume that the method you use is the same as that outlined in the proposed methods for 
the cooperative work on the sample of beef extract sent out June 3, 1907. Our results 
on this cooperative work, as well as our analyses of several other samples, give materially 
low(:'r figures for total kreatinin << liy the method furnished us by Mr. Cook in his letter 
of June 3 than by the method of Grindley and Woods. 

We also note that the percentage of proteid^ as determined in fluid extract of heel is 
not proportional to the proteid as determined in solid extract. Inasmuch as one is 
made from the other Ijy mere solution in water, we are unaljle to find an explanation 
for this difference, assuming that both were determined by the same method. We 
note also that the total nitrogen in these two preparations is not proportional. 

Among other features that we note we shall mention only the unusually high moisture 
in Soluble Beef. It is considerably higher than our records. 

Comment ly authors. — The fact that some of the results var^' with 
the method used has ah-eady been discu.ssed, and this is especiaUy the 
case with kreatinin. As tlie same method was appHed to all the sam- 
ples reported, no injustice is done. 

The percentage of moisture and total nitrogen in the solid and fluid 
extract are proportional, but the percentage of total proteids in the 
fluid extract is lower than in the solid extract. This, however, is 
compensated for by a correspondingly higher percentage of 'meat 
bases. This may be due to the failure of the tannin-salt reagent to 
precipitate all of the proteid, and consecpiently a higher meat base 
result is obtained. 

BovRii, Limited. 

No. 15909. 

W'e have to thank you for your favor of September 21, but we can not help thinking 
that there has l)een a inisunderstaiuling somehow, for our standard for moisture and 
ash'' in Johnston's Fluid Beef is 32 per cent and 19 per cent, respectively. 
A careful analysis of the last three batches made has given— 

Mnistun*. .\.sli. 

No. 1 33. (i9 19.34 

2 31.22 IS. SO 

3 32. 61 19. 20 

We are under the impression that llie sample you have analyzed is a cordial and 
not the original Johnston's Fluid Beef. The latter is a paste standardized as aliove, 
whereas the cordial i:; a liquid prepared with a higher percentage of moisture for con- 
venient use in saloons, etc. 

Coiiunent by authors. — The product reported under No. 15909 was 
labeled as "Johnson's Fluid Beef." Owing to the statement of the 
manufacturer, a new sample was obtained on the market and the 
moisture and ash determined again. This sample contained 38.62 
per cent of water and 13.18 per cent of ash. 

« See Tables II, IV. and IX. 
!> See Tables III, V, and X. 
« See Table IX, page 26. 



COMMENT BY MANUFACTURERS. 11 

The Cudahy Packixo Company. 

Nos. 15SW .ind 15979. 

For your information we wish to say that the Extract of Beef we are now putting on 
the market is, in our estimation, a superior article to the preparation we were sellini,' at 
that time, and we are having an analysis made of our present iiuinulail\u'e and will 
sulimit the figures to you as foon as completed. 

LiBBY, McXeili. and Libby. 



In replyto your favor of .September 21 , in reference to your analysis of our Premier 
Brand Extract of Beef, will state that we have carefully examined our analyses for an 
extended period and find that our determinations are not in accordance with your 
analysis. You, of course, recognize that in the making of this product there is sure to 
be considerable variation and we feel sure your Department does not expect each 
batch to be an exact duplicate of every fjther one. * * * 

We have had our chemist analyze samples from our present stock and sulmiit the 
following, whicharetheaverageof his determinations of the various samples analyzed — 

for cent. 1 I'.T ivnt. 

Moisture 19.54 | Total nitrogen 7.(50 

Ash 27. 80 I Ether extract .53 

Sodium chlnrid 11.32 j Lactic acid 7.!i7 

Proteid 13. 12 j Ammonia .50 

Meat bases 18. 12 , Undetermined 12. 3-1 

Total kreatinin .5. 40 

Comment hy authors. — An uiisiicce.s.sful atteiiii)f wn.s niailc to sociirp 
another sample of this product. 

II. K. MuLFonn ('omi-any. 



X comparison of the results with analyses on record in our laltoratory agree quite 
well in the main. * * * Some eighteen months ago we revised our lal>el aiul litera- 
ture on Predigested Beef iitan effort to have our statements conservative and in accord- 
ance with the standards established through assay of the linished product. 

P.^RKE, Davls and Company. 

Nos. 15970 and 15991. 

Acknowledging the receipt of your two reports ujjon Mosqtiera Beef .Telly (Extract 
of Beef) and Mosquera Fluid Beef .Telly, we beg to say that we ha\e no jjarticular criti- 
cism to offer to the results as outlined any further than to say that they agree in a gen- 
eral way with the data which we have obtained and which ha\'e been (jbtained by 
others in the analysis of these two products. * * * You of course realize that the 
results obtained from the analysis of different samples of beef extract will vary, and 
the same is ecpially true of the results obtained by different operators. Furthermore, 
the results as expressed vary according to the method of assay emjilnycd, particularly 
as regards the interpretation placed upon the content of nitrogen. 

* * * We presume to suggest that the estimation of a total acidity of beef extracts 
as lactic acid will be regarded by analytical chemists a.s somewhat of an innovation. 
This is certainly calculated to work some injustice in the case of our beef extracts, 
inasmuch as fruit acids are incorporated through the use of the pineapiile juice em- 
ployed in the jirocess of manufacture. 



12 MEAT EXTRACTS. 

May we ask, therefore, that you will incorporate in your final report some note to 
the effect that the total acids of the extract are calculated as lactic acid, and further- 
more a statement that "Juice of partially ripened pineapples is employed as a digestant 
in the manufacture of Mos()uera Beef Extract." The high percentage of acidity is 
probably therefore accounted for by the acidity of the pineapple juice. 

Comment hy authors. — The points raised as to method of stating 
acidity are ehici(hxted by table lieadings and context. 

James P. Smith and Company. 

No, 1.5978. 

We have not imported the article labeled "Maggi Bouillon" since November, 190G, 
as under the advice of your Dei)artment we changed the label .so that it read "Maggi 
Essence." 

It is not a food prcjduct in the general acceptation of the term, l)ut an essence which 
is added in very small quantities as an improver to insipid soups, weak liouillon, etc. 

John Wyeth and Brother. 

No. 159G5. 

In comparing the results of your analysis with the figures obtained iu our own labo- 
ratories, as well as with the analysis made some years since liy Dr. Fresenius, of Wies- 
baden, we are glad to say that in a general way the three analyses agree, particularly 
in view of the fact that doubtless the methods used in the different determinations 
have varied to some extent. The only appreciable difference we notice between your 
analysis and that of Fresenius is in the percentage of meat bases,'' which in his analysis 
is reported as 14.33 per cent as against your 5.99 per cent, but we find tliat this is due 
to a difference in the factor employed, that used Ijy Fresenius being ().25, while you 
have used the now generally accepted factor 3.12 in calculating the meat bases. We 
have ourselves determined the meat bases as amounting to 8.2(i per cent, by precipi- 
tating the total proteids with bromin, deducting the percentage of nitrogen which 
they contain from the total nitrogen and nuiltiplying the difference by the factor 3.12. 

MEAT EXTRACTS. 

Tentative Standards. 

The following standards were issued for criticism by the Committee 
on Food Standards of the Association of Official Agricultural Chemists, 
on November 19, 1906, but have never ])een uificially promulgated by 
the Department. 

SOLID MEAT EXTRACT. <■ 

1. Meat extract is the product olitained liy extracting meat with boiling water and 
concentrating the li<|uid portion by evaporation after the removal of fat, and contains 
not less than seventy-five (75) per cent of total solids, of which not over twenty-seven 

a Acidity of sample No. 15976 given in Table IX: No. 15991 in Talile X. 

b See Table X, page 27. 

<^ Subsequent action by the Joint Committee on Food Standards, representing the 
Association of Official Agricultural Chemists and the Association of State and National 
Food and Dairy Departments has modified the standard to read "not less than 8 
per cent is nitrogen," inserted the word " Fre.sh " before the word "Meat" in the 
first line, and added the words "and kreatinin" in the last line. These changes 
have not been officially promulgated. 



METHODS OF PREPARATION. 13 

(27) per cent is ash and not over twelve (12) per cent is sodium chlorid (calculated 
from the total chlorin present), not over six-tenths (OJi) per cent is fat, and not less 
than seven (7) per cent is nitrogen. The nitrogenous compounds contain not less 
than forty (40) per cent of meat liases and not less than ten (10) per cent of kreatiu. 

KHIII MKAT K.XTHACT. 

2. Fluid meat extract is identical with meat extract except that it is concentrated 
to a lower degree and contains not more than seventy-five (75) and not less than 
lifty (50) per cent of total solids. 

In connection witli these tentative staiulai'd.s, the foUowino; reciiii- 
sites for a meat extract given by Liohig" afe of interest: 

1. A gooil extract shoidd contain nci albumin and no fat (the latter not al>ove 1.5 
per cent>. 

2. The water content should not exceed 21 per cent. 

3. About 60 per cent should be soluble in 80 per cent alcohol. 

4. The nitrogen content should run from 8.5 to 9.5 per cent. 

5. The ash should vary from 15 to 25 per cent, which, besides a little sodium chlorid, 
consists principally of phosphates. 

MeTIKID.S ok PltEP.\R.\TlllN. 

Up to a few years ago the soii]i lifjiior obtained from meat which 
was parboileil in tiie process of prepaiing canned meat was entirely 
wasted, but this liquor is now extensively utilized in the manufacture 
of extracts and preparations of meat. In preparing canned meat 
pieces of meat are placeil in iron baskets which are suspended in large 
tanks containing cold water. Steam is admitted and tiie meat 
heated about one-half hour (thirty to forty minutes). The lifjuor, 
which is the source of meat extracts, is pumped into triple-eflect 
vacuum pans and heated at 160° F. for about four hours. Tlieii the 
solution is transferred to a single-effect finishing kettle and heated 
eight hours until the water content approximates 22 per cent. 

A first-grade extract of beef is prepared from beef alone anil is 
usually sold in jars. An extract of the trimmed bones, to which 
consideralile meat adheres, is also made. Tlic trimmings include 
odds and ends of meat, muscle tissue, bone, etc., and the product is a 
second-grade article. In preparing this extract the bones are heatetl, 
not boiled, for thirty to forty minutes, and the liquor evaporated to 
the consistencj' of extract. The extract prepared from corned beef 
liquor constitutes another second-grade product. This extract has 
a high content of nitrates and sodium chlorid. In addition there is 
an extract prepared from pork and other meats, sold under the gen- 
eral term of meat extract. Mixtures of the various meat ami bone 
extracts are often made. A fluid meat extract is usually a 50 per 
cent solution of a solid extract. 

«R6ttger, Lehrbmdi der Nahrungsmittel-< 'hemic, p. 135. 



14 MEAT EXTRACTS. 

Assuming tliat bocf extract contains 21.7 per cent of water, tliere 
is obtained from 100 jroiinds of "soup liquor" 1.94 pounds of com- 
mercial meat extract." These figui'es are high, as thej^ are calcu 
latetl from the total solids present in soup liquor. The manufac- 
turers claim that 100 pounds of "soup liquor" will yield 1 pound of 
meat extract. 

In speaking of the preparation of meat extracts, Charles R. Valen- 
tine '' states that when raw meat is finely chopped and macerated in 
the same weight of cold distilled water and squeezed out, the water 
dissolves from 16 to 24 per cent of the weight of the dry flesh. If the 
water infusion is heated, the albumin of the flesh separates as a 
flocculent precipitate when the temperature of 133° F. is reached, and 
the red coloring matter of the blood, likewise albuminous, coagulates 
at 158° F. The infusion, or extract of flesh, from which the coagu- 
lated albumin has been strained, when evaporated at a gentle heat 
jjecomes darker in color. When it is dried there is obtained a browai, 
rather soft mass amounting to 12 or 13 per cent of the original flesh. 

Valentine says it is not claimed that extract of meat is a food, but 
that it contains the extractive matter and salts of a large quantity of 
beef and possesses certain medicinal and dietetic properties. From 
about 32 pounds of lean beef, free from fat and bone, equal to 8 
]iounds of dry meat and 24 pounds of water, 1 pound of true extract 
of beef can be made. A good extract should always have an acid 
reaction, its color should be a characteristic yellowish brown, and it 
should have an agreeable meat-like odor and taste. It should be 
entirely soluble in cold water, and free from albumin, fat, and gelatin. 

Solid Me.\t Extracts. 

The percentage of nitrogen with its distribution in the various 
nitrogenous bodies is given in Tables II and III and throws much 
ligiit on the quality of the extract. The meat products examined 
are divided into four classes, i. e., solid and fluid meat extracts, 
meat juices, based on the definitions of the standards committee, and 
miscellaneous pre])arations. Of the six solid meat extracts reported 
in Table II, several fall below the ilefruition in one or two points. 
They, nevertheless, closely adhere to them in most respects, the 
percentage of nitrogen present in the form of total meat bases and 
kreatinin nitrogen being sufliciently high. 

The figures in Table III are obtained by calculation from those in 
Table II, and represent the percentages of nitrogenous bodies present 
expressed both as ])er cent of total nitrogen and as per cent of sample. 
In order to obtain the nitrogenous bodies from the corresponding 
nitrogen figures the following factors were employed: For insoluble 



n IT. S. Dept. Agr., Bureau of ("hemistry. Bui. 13, Part 10, p. 1390. 
6 J. Soc. Arts, 1897, 4<J : 430. 



ANALYSIS (.)F SOLID MEAT EXTKACTS. 15 

and foagulablc proteiil, ])rotei)si's, and ix'ptunes tlic I'lictdr (i.LT) was 
used. To obtain total meat bases, total kreatinin, and the meat 
bases other than kreatinm and xanthin, the factor 3.12 was employetl. 
The xanthni factor used was 2.71 and the ammonia factor 1.2143. 

Fluiu Meat Extracts. 

The analysis of these preparation.s is given in Tables IV and A'. 
As was the case with the ;solid meat extracts, not all of the pri)ilucts 
inckuled under Table IV correspond in every detail with the dclhution 
of the standards committee for fluid meat extracts. The solids 
according to the definition should run from 50 to 75 per cent. Several 
extracts in Tables I\ and V are l)elow the minimum figure. The 
price of some of these jiroducts is even greater than the price of meat 
extracts notwithstanding the fact that (he water content is much 
higher. 



16 



MEAT EXTRACTS. 



-5> 
I 



a 



6 

CO 






^1 


goOOOt^-* WOJ 

gSBSgss 


T3 is 

a <u a 






a!" 


a 


^ O OS 


Jl^ N e*3 N ^ t^ CI 


oi S * 3"!:^-^ i c 
fi§5.aSS«2 


t; Jo 1:0 <N o .-1 ■* 

^ ci ci M c-i oi c-i 

a. 


c S S 

x5s 


-^ 00 CO 'J' ■-< "O iM 

t- CO .-H ■«• 10 

r 






gel 


^ CO CO CC CO CO ■fl' 


&5J 






tsSSSKSS 
a, 


C D ci g c3 


r 


3£d 


<>J r^ 0^ i^ io -J5 




2_: 


■5^ -H CO M 10 10 33 




^ ^ '£> n t- to •-> 

^ g '-D oi CR >0 -"P 1-^ 


m 

1=1 

CD 

3 

n 
o 

g 

03 

i 


M tlIlP,-g,Oi 


tj 01 r- oi t^ Oi 
^J w rH -* CN ci ci 




■*: 10 .-1 01 Tf 00 -H 

■i* CO ■* (M i-f (M 

to 

a, 


— 1 ^ 
2gg2 

H ao.a 


5u cJ ci -^ ci ci CO 


-cAfi2.B 


■-C ^ —1 1— — 1 10 

(J »0 « -^ CO 10 C-l 

5; 06 CO to 06 CO CO 




t, Cl M C* CO (N CO 


il 


ft, 01 M 01 M M ^ 




6 

CO 


>o 'O "O '-: '-0 » 



C 
■M 

'5 
•5 


"o 
tn 

s 

a 

X 

03 
03 

1 


g 

,03 

'3 


a 


Si 


1 ei 


Per ct. 
2.74 
4.08 
2.74 
7.14 
10.76 
3.64 


Meat 

bases 

other 

than 

kreatin, 

kreat- 

inin.and 

xanthin. 


Per cent. 
31.64 
29.22 
29.50 
34.55 
32.88 
35.71 


Xanthin 
bases. 


Per cent. 
5.21 
.33 
.52 
1.83 
6.82 
7.58 


Kreatin 

and 
kreat- 
jnin. 


Per cent. 
11.92 
12.57 
9.79 
16.78 
12.27 
18.08 


gas 


Per cent. 
48.77 
42.12 
39.82 
53.16 
51.97 
61.37 


(£0 


Per cent. 
21.51 
29.55 
24.80 
22.09 
16.52 
21.57 


i i 


Per cent. 
22.60 
22.16 
26.37 
12.79 
15.45 
12.54 


Insoluble 

and 
eoagula- 

ble 
proteid. 


Per cent. 
4.38 
2.09 
6.27 
4.82 
5.30 
.87 


Am- 
monia. 


Per ct. 
0.24 
.45 
.26 
.52 
.86 
.30 


Meat 

bases 

other 

than 

kreatin, 

kreat- 

inin. and 

xanthin. 


e c^ ci Ti« t~ CO 

S t~^ OC t-^ CO t^ 

1^ 


Xanthin 
bases. 


Per cent. 

1.03 

.08 

.11 

.30 

1.22 

1.41 


Kreatin 

and 
kreat- 
inin. 


Per cent. 
2.71 
3.56 
2.34 
3.15 
2.53 
3.87 


03 eS « 

gal 


Per cent. 
11.11 
11.92 
9.52 
9.98 
10.70 
13.14 


g-1 


Per ct. 
9.81 
16.75 
11.88 
8.31 
6.81 
9.25 


si 


Per ct. 
10.31 
12. .50 
12.63 
4.81 
6.38 
5.38 


Insoluble 

and 
coagula- 

ble 
proteid. 


Per cent. 
2.00 
1.19 
3.00 
1.81 
2.19 
.38 




Per ct. 
22.12 
30.50 
27.51 
14.93 
15.38 
15.01 




6 

1 


15867 

15868 

15869 

16048 

16049 

16060 



ANALYSIS OF FLUID MEAT EXTKACTS. 



17 



a I :;• 



P. 


1 


. .— o -c ■.-: i.-; "-c o 
t'^ I* o r- cc CO "T 1.1 


Net 
weight. 


Grams. 
105.7 
68.0 
69.7 
03.5 
73.7 
102.2 
127.4 


Unde- 
ter- 
mined. 


Per ct. 
9.75 
8.12 
15.12 
12.14 
0.60 
2.04 
3.54 


Ether 

ex- 
tract. 


Per cl. 
0.09 
.23 
.50 
.04 
.05 
.06 
.09 


Cl 


Am- 
mo- 
nia. 


t; — p Ji ^^ p QC. CO 


Meat 
bases 
other 
than 
kreatin 
and 
xan- 
thin. 


Per ct. 
1.05 
1.40 
1.37 
1.37 
1.79 
.77 
.04 


|l| 


Per ct. 
0.23 
.26 
.22 
.17 
.04 
.09 
.08 


Kreatin 

and 
krent- 
inin. 


Per cl. 
0.38 
.20 
.35 
.48 
.80 
..50 
.20 


Total 
meat 
bases. 


Perct. 
1.60 
1.92 
1.94 
2.02 
2.63 
1.30 
.98 


P. a) 


Per ct. 
0.70 
.47 
.77 
.74 
.41 
.89 
.91 




Per cl. 

0. 34 

.10 

.10 

.54 
.44 
.31 


Insol- 
uble 
and 

coagu- 
lable 
pro- 
teid. 


*: -* -.o CO Cl t^ -^ 00 

VO"^OC^-.<COO 


Total 
nitro- 
gen. 


Perct. 
2.85 
3.15 
3.06 
3.87 
3.9.5 
3.18 
2.41 


.\s 
lactic 
acid. 


Per ct. 
3.11 
3.92 
4.53 
4.76 
4.92 
2.43 
2.20 


N/10 

sodiiun 

hy- 

drox- 

id. 


cc per 
gram. 
3.46 
4.35 
5.04 
5.29 
■ 5. 51 
2.70 
2.45 


c 

o 
o 

2 

i 


Inor- 
ganic 
phos- 
phoric 
acid. 


Per cl. 

2. 06 
3.23 
2.96 
2.83 
2.10 
.81 
.02 


Or- 
ganic 
phos- 
phoric 
acid. 


t° 

a. 


Total 
phos- 
phoric 
acid. 


Per ct. 
2.32 
3.27 
3.41 
3. -29 
2.48 
.95 
.80 


Chlorin 
as so- 
dium 
chlorid 
in ash. 


Per cl. 
8.27 
0.71 
1.77 
7.02 
8.4.8 
11.38 
10. 05 


ii 


Perct. 
17.23 
10.21 
10.20 
15.91 
10.99 
16. 13 
13.85 






Per ct. 
57. 75 
.58.84 
57. 04 
49. 94 
,55. 99 
04. 03 
08.97 




6 


1.5904 

1.5905 

1.5906 

15977 

1.5979 

15990 




436S9— Bull 114—08- 



18 MEAT EXTRACTS. 

MEAT JUICES. 

Tentative Standard. 

Meat juice is defined by the standards committee of the Associa- 
tion of Ollicial Agricultural Chemists as the fluid portion of muscle 
fiber obtained by pressure or otherwise, and may be concentrated by 
evajjoration at a temperature lielow the coagulatini; point of the 
soluble proteids. The solids contain not more than fifteen (15) per 
cent of ash, not more than two and five-tenths (2.5) per cent of 
sodium chlorid (calculated from the total chlorin present), not more 
than four (4) nor less than two (2) ])er cent of jihosjihoric acid (P^Oj, 
and not less than twelve (12) per cent of nitrogen. The nitrogenous 
bodies contain not less than thirty-five (.35) per cent of coagulable 
proteids and not more than forty (40) per cent of meat bases. 

Discission <if Hesui.ts. 

8everal of the j)rcparations included in miscellaneous prepara- 
tions (Table IX) were advertised as meat juices. During the 
autumn of 1906 several samjiles of meat juice were prepared in the 
laboratory. Large samples of round and chuck beef were made 
practically fat free, cut into small pieces with a knife, and one sample 
of each pressed in the cold through cotton bags in a glycerin cylinder 
press. Another sample of each was heated at 60° C. in large jars 
for several hours, then pressed as above described. The analyses 
of these four samples and of several other samples of meat juices 
jirepared in various ways in the laboratory are given in Table VI. 

A meat juice naturally varies according to its mode of prepara- 
tion, and more juice is obtained by heating the meat to 60° C. than 
by extracting in the cold. In the case of the sani])les made in the 
laboratory practically one-half the nitrogen is in the form of coagu- 
lable proteitl nitrogen. In several cases a considerably larger por- 
tion is in that form. 

A meat juice is characterized by a high content of coagulable pro- 
teids and a low content of meat bases. Of the so-calletl commercial 
meat juices in Table IX none shows any appreciable amount of coagu- 
lable proteid. They are, therefore, not correctly designated by the 
name meat juice and their nutritive value is misrepresented by 
such designation. It appears impracticable to prepare a true meat 
juice for market, as the temperature necessary for the ])reservation 
of food products in hermetically .sealed packages coagulates the 
proteids and changes the nature of the product. The fact that 
when these higher forms of nitrogenous bodies are removed the 
valuable nutritive principles of the juice are lost must be recognized, 
and a })roduct so altered should not be designated as a meat juice. 



ANALYSIS or LABOKATOKY MEAT JUICES. 



19 



In muscle tissue there is found iqiproxinuitely 75 per cent of water. 
Of the 100 parts of nitrogen in beef, 75 j)arts consist of proteid mat- 
ter insohible in water; 10 parts consist of water-sohible proteid, and 
12.5 parts of extractives, which are also water soluble. Unfortunately 
in making these analyses the total kreatinin was not determined. 
A.S before stated, all of these juices are characterized by a large 
amoimt of coagulable proteid, wliile the percentage of the other 
constituents present seems to vary with the water content. The small 
amount of sodium chlorid in the ash is noticeable, and the amount 
of nitrogen present in the form of albumoses and peptones is small, 
as would be expected in a true meat juice. It is evident from Table 
VI that there is considerable water-soluble amido nitrogen present 
in the juice of meats. 

Tahle VI. .\l<'(:l juices jirr/iarcd in laborattinj. 



yerial 
No. 



17(W1 
17002 
17W11 
17ll',12 
19766 
19767 

19785 

19786 

19787 



Serial 
No. 



17091 
17092 
17091 
17092 
19766 
19767 

19785 

19786 

19787 



I'repiiriitiou of juice. 



Round hoof, cold pressed 

("huck beef, cold pressed 

Round beef pressed at 60° C 

Cliuclc tx'of pressed at 60"^ C 

.luioo from lioef chuck at 60° C... 
Juice pressed from sirloin steak 

and water 

Juice extracted from sirloin 

steak by cold pressure 

Juice ('xtrnelod from beef chuck 

h\ cold [Mi'ssuro 

Juicf ixira.lod from beef chuck 

bv cold pressure after 6 hours 

at eo^-lOflo C 



Composition of sample 



Water 
in juice. 



Preparation of juice. 



Round beef, cold pressed 

Chuck beef, cold pressed 

Round beef pressed at 60° C 

Chuck beef pressed at 60° C 

,Iuice from beef chuck at 60° C. 
Juice pressed from sirloin steak 

and water 

Juice extracted from sirloui 

steak by cold pressure 

Juice extracted from beef chuck 

by cold pressure 

Juice extracted from beef chuck 

bv cold pressure after 6 hours 

at 60°-10U°C 



Per cent. 
85.76 
86.85 
'.n. 65 
91. ',10 
89. .50 

91.10 

96. i:i 

96. m 

98.11 



Chlorin 
as so- 
dium 
chlorid 
in ash. 



Per cent. 
1.6.'! 
1.86 
L.'Se 
1.29 
1.27 

1.40 

.46 

.■li! 

. :;9 



Per cent. 
0.12 
.20 
.15 
.19 
.16 

,12 

,1)5 

.05 



Phos- 
phoric 

acid 
CP2O5). 



Per cent. 
0.37 
.,31 
,36 
.29 
,37 

,1.'! 

.14 

.11 



Ether 
extract. 



.\eidity 

as lactic 

acid. 



Per cent. Per cent. 
0.27 ] 0.27 

30 . ,32 



.15 

,20 



Composition of sample. 



Total 
nitro- 
gen. 



Per ct. 
2. 08 
1.74 
1. 10 
1.09 
1.09 

1.18 



Insolu- 
ble 
nitro- 
gen. 



Per ct. 

0.16 

.29 



Coag- 
ulable 
nitro- 
gen. 



Per ct. 
1.37 
.98 



.19 
.54 
.34 
.34 



Proteose 


Peptone 


,'\niido 
nitro- 
gen. 


nitrogen. 


nitrogen. 


Per ct. 


Per ct. 


Pent. 


0.fl6 


0.11; 


I). .« 


.07 


. 11 


.29 


.04 


.01 


.43 


.07 


.21 


.27 


.42 
.20 




.18 
.20 


.18 


Trace. 


None. 


.14 


Trace. 


None. 


.l/J 


Trace. 


.12 


.08 



Undo- 

tor- 
nnnofl 
matter. 



Per ct. 

0.47 

1.03 

1.90 

.4(1 



20 



MEAT EXTRACTS. 



Taijle \l.^ Meat juices prepared in laboratory — C(in1iiUK*<l 



Serial 
No. 



I'repamtion of juice. 



Results in temis of total nitrogen. 



Insol- 
uble 
pro- 
teid- 



Coag- 

ulabie 

pro- 

teid. 



Albu- 
moses 



Pep- Amide 
tones. [ bodies. 



Nitrogenous bodies. 



Insol- 
uble 
pro- 
teid. 



Coag- 

ulable 

pro- 

teid. 



Pro- 
teoses. 


Pep- 
tones. 


Per ct. 


Per ct. 


O.-iS 


1. (Kl 


.44 


.BO 


.25 


.Of. 


.44 


l.:il 


■>. (Ki 




1. LT) 


1.13 


Tr-.uv. 


None. 


'I'ni«>. 


None. 


Trace. 


.75 



Ainido 
Jjodies, 



17091 
170112 
170U1 
170U2 
19766 
19767 

19785 

197S6 

197S7 



Round beef, cold 
pressed 

Chuck beef, cold 
pressed 

Round beef pressed 
at 60°r 

Chuck beef pressed 
at eo'C 

Juice from beef 
chuck at 60° C 

Juice pressed from 
sirloin steak and 
water 

Juice extracted from 
sirloin steak by 
cold pressure 

Juice extracted from 
beef chuck by cold 
pressure 

Juiceextracted from 
beef chuck by cold 
pressure after 6 
hours at 60°-100°C. 



7.69 



Per ct. 

65.87 



50.32 



11.01 37.61 



Per ct. 



3. 45 



Per ct. 

7.69 
6.32 



Per ct. 

15.87 
16. 66 
37.07 
24. 77 
16. 51 

22. 03 

29. 17 

20. 93 

33. 33 



Per ct. 

I.(K) 

1.81 

4 



Per ct. 
8.56 
6.13 



;. ih; 
;. 3s 

!. 13 

:. 13 



Per ct. 
1.03 
.90 
1.34 

.84 
.56 

.81 

.44 



YEAST EXTUACTS. 

M.\NlIKA(.-TtIRE ANIJ I^SK OF YeAST ri!EI'ARATI(lNS. 

Yeast oil hydrolysis yiekls extractives wliich are similar to those 
obtained from meat. For many years yeast extracts have appeared 
on the market, especially in Germany, and have also been mixed with 
and used to adulterate meat extracts. Such products are now manu- 
factured in tliis country to a limited extent. The water extract or 
infusion of yeast, when evaporated in the open-kettle process, darkens 
and looks like an extract of meat. Caramel is sometimes addetl to 
further deepen the color. Wlien the process of evaporation is allowed 
to go too far, a bitter taste appears, wliich is due to the peptones 
formed, and it is claimed this may be removed by washing with water 
and dilute ammonia solution. In general the preparaticm of an 
extract of yeast is similar to that of an extract of meat. In an extract 
of yeast the liigher nitrogen forms are more abunilant than in meat 
extract. Two samples of yeast extract examined contained 5.68 and 
5.67 per cent of total nitrogen. In regard to their stimulating effect 
and general action on the body the two extracts (meat and 3'east) are 
practically identical according to Wintgen,'' and their value as a 
proteitl sparer depends only in part on their nitrogen content. 



oAbs. Pharm. Ztg., 1905, jO:432. 



DETECTION OF YEAST EXTKAt'TS. 21 

MuTHdDW OF DeTECTIdN. 

Searl "■ suggests as a method for detecting yeast products added to 
meat prejjaralions, that a sohition of the extract be boiled one or two 
minutes with a modified Feliling's sohition. In the presence oi yeast 
extract a bluish-white precipitate is obtained. Arnold and Mentzel '' 
claim that a slight bluisli-wliite precipitate is given even with pure 
meat extracts, but by experience an analyst learns to detect by this 
method the presence of about 20 per cent of yeast extract in meat prej)- 
arations. Micko<^ suggests the determination of kreatin and xanthin 
bodies as a means of determining the nature of the extract. Wintgen'' 
states that the iiltrate from the zinc sulphate precipitate obtained 
in the determination of albumoses is entirely clear in the case of meat 
extracts, but somewhat turbid with yeast extracts. Tliis he finds to 
be true even when the best S. & S. filter paper is employed. By this 
method the authors could detect fi'om 20 to 30 per cent of added seast 
extract. 

E. Baur and II. Barschall' have applied the colorimetric test, as out- 
lined by Folm, for kreatinin to meat and yeast extracts. They find 
no kreathi or kreatinin in yeast extracts and base a distinction 
between the two on ibis test. wSalkowski '' has studied the various 
carbohydrates of yeast and gives several tests for j'^east gum. 

The most reliable test is unquestionably the determination of 
la-eatm. A yeast extract contains no kreatin and in a typical meat 
extract there is foimd from 10 to 20 per cent of the total nitrogen in 
the form of la-eatin and la'catinhi. The distribution of the various 
xantlihi bases als(j is different in the two kinds of extracts; in meat 
extracts, according to Micko,'' xanthin and hy])oxanthin predominate, 
while in yeast extracts adenin and guanin predominate. 

Re.sukt op Tests. 

A test for yeast extracts consisting in boiling tlu^ samples for one or 
two minutes with an umnodifie(l Fehling's solution was tried. Four 
samj)les were tested with the following a^sidts: 

Color of prccii>il:i1(>. 

A. Meat i-xlracl Very deep viiilel, color. 

B. Yeast extrael Very deep griM-ii color. 

C. .'iO per cent yeanl and 51) per cent meal extract Intermediate colijr. 

D. 12-5 per cent yeast and 75 i)er cent meat extract Violet color, not as 

strung as A . 

This test is of value as a qualitative and a confirmatory test for 
yeast extracts in the presence of meat extracts. 



" Pharm. .T., 1903, 7/:51G and 7(W; 190!, 7.':S(i. 

*- Pharm. Zt-., 1904, 49:l'lli. 

<-Zts. Nahr. Genussm., 1902, .5:193; 1903, «:7S1. 

(iArch. Phann., 1904, i'.ii':537. 

<" Arb. kaiserl. Gesundheitsamte, 190(i, i'.;:.5(i2. 

/Per, d. ohem. fies., 1894, L»7:499, 

;/Loc. cil. 



22 MEAT EXTRACTS. 

The method of Searl for the detection of yeast extract by the use of 
a modified Felding's sohition was also tested. The method is as 
follows: 

Prepare a modified Fehling's sohition by dissolving 200 grains of copper sulphate 
and 250 grains of neutral taitrate of sodium in 4 ounces of water. Add to this 250 
grains of sodium hydroxid dissolved in 4 ounces of water. Dissolve 10 grains of the 
sample to be examined in 1.5 ounces of water, add to this one-half volume of the above 
solution and boil for one or two minutes. With genuine meat e.xtract no precipitate 
is given. Wlien yeast extract is present a curdy, bluish-white precipitate is formed. 

Tills method was tested on a sample of meat extract, a yeast ex- 
tract, a 50 per cent .solution of yeast and meat extract, and a solution 
containing 20 per cent of yeast and SO per cent of meat extract. In 
the case of the meat extract a veiy fine precipitate was olitained. 
In the three cases where yeast extract was present a flocky,l)hush- 
white precipitate was formed. It is evident from these results that 
the presence of 20 per cent of yeast extract in meat mixtures may 
be detected by this method. 

Searl also gives a modification to be applied when doubtful results 
are obtained by the original method. In such cases 3 to grams (50 
to 100 grains) of the sample are dissolved in from 4 to 8 cc (1 to 2 
drams) of water. Alcohol is added to precipitate the proteid matter, 
the solution is thoroughly shaken, and filtered. The residue is dis- 
solved in 45 cc (1.5 ounces) of water, filtered if necessary, and the 
usual method applied. 

This modification was tried on 10 and 20 per cent mixtures of yeast 
extract, but the residts obtained were not satisfactoiy, and it is 
doul)tfid if less than 20 per cent of yeast extract can be detected in 
the presence of meat extract by this method. 

Another test is described by Wintgen," who claims that the zinc 
sulphate filtrate in the case of meat extracts is clear, ])ut with yeast 
extracts it is turbid. This was found to be the case, as the following 
results show: 

Zinc sulphato filtrate, 

A. Meat extract Clear. 

B. Yeast extract Clon<ly. 

f. 50 per cent yeast and 50 per rent meat extract < 'loudy. 

D. 25 per cent yeast and 75 per cent meat extract < ioudy. 

The solutions of these extracts, or mixtures, were saturated with 
chemically pure zinc sulphate after adtling two drops of strong sul- 
phuric acid. The solutions stood over night and the filtrates were 
examined in the morning. The only clear filtrate obtained was that 
from meat extract alone. 

The most important test for determining the nature of an extract, 
whether meat or yeast, is the determination of kreatin and kreatinin. 
This test, which has been used in the Bureau of Chemistiy for two or 

« Arch. Pharm., 1904, 242:537. 



DETERMINATION OF KREATININ. 



23 



three years and found to Ix' of great value, was perhaps first apphed 
by Micko." As before stated, yeast extracts contain no kreatin or 
kreatinin, while in meat extracts these two Ixxlies are present in con- 
siderable amounts. 

Some experiments on meat extract, yeast extract, and mixtures 
of the two were tried with satisfactory results, using the Folin'' culori- 
metric method. In determining the kreatinin bj^ this method in tlie 
presence of yeast extract, slightly higher results are obtained than 
when yeast extract is not present. V\'hen the kreatin and kreatinin 
arc determined together (after dehyilrolysis) in a sample of meat 
extract the presence of yeast extract does not seem to affect the 
results. In the case of the yeast extract no kreatin or kreatinin was 
found, as is shown in Tables VTI and VIII. 

T.\BLK \\l.- Kr<(ilinin in. meal iiiiil iiiiixl rilracts. 



No. 



Description of .symjilo. 



Meat extract . 



Average . 



Yeast extract 

Mixtvire— .50 per cent meat and 50 per cent 
yeast extract 



.\verage . 



Mixture — 75 per cent meat and 25 per cent 
yeast extract 



.\verage. 



Weight 


Kreatinin. j 


of 
sample. 


Weight. 


Per cent. 

3.39 
3.31 


Grams. 

0. 2t)(i0 

. 20(13 


Mg. 
S.S04 
8. 804 



Kreatinin 

calculated 

to meat 

extract 

used. 



Increase of 
kreatinin 
due to pres- 
ence of 
yeast ex- 
tract. 



I 



Per cent. 
3.39 
3.31 



.1800 

. 4154 7. 788 

.3750 7.013 



.2038 I 8.437 
.3030 I 7.941 





1.87 
1.87 



3.35 



.3.75 

3.75 




0.40 



3.19 
2.62 



4. 25 
3.49 



T.Msi.E VIII. — Total trialinhi {iiicliiiliiui kri'iiliii i-diiicrlcd to hreatinin) in meat iiiiil 

yeasi olriifls. 





Description of sample. 


Weight 

of 
sample. 


Kreatinin. 


Kreati- 
nin cal- 


Increase 
of kreat- 


Kreatin 
calculated 
as kreat- 
inin (by 
difference). 


No. 


Weight 


Per 
cent. 


culated j'""'tn 
"'^'^''- 1 extract. 


1 


Meat extract . . 


Grams. 
|0. 2210 
I .2144 


Mg. 
11.571 
9. .870 


6.24 
4. no 


Per cent. ' Per rent. ' Per cent. 
5.24 1 4.92-3.35 










, -..,„ 












4. 92 4. O") 






9 


Yeast extract 


ill 




11.571 
9.fi91 




2. 04 
2.41 




5.29 

4.82 




o.is' 





3 


Mixture— 50 per cent meat and 5lt per cent 
yeast extract 


1 5. 05-3. 75 
1 =1.30 










•' .53 


5.05 
5 S5 






4 


Mixture— 75 per cent meat and 25 per cent 
yeast extract 


f .3554 
\ .3255 


15. 577 
10.385 


4. as 




1 5. 05-3. 87 
1 —1. 18 




3.19 4.25 


.13 














3 79 


5. 05 



















t' Loe. cit. 



^Zts. physiol.Chem., KiU4, 4/.-22;{. 



24 MKAT EXTRACTS. 

MISCELLANEOUS PREPARATIONS. 

('l,A.SSIFICATION. 

In Tables IX and X are reported all commercial samples examined 
which do not fall under either Taltle II or Tahle IV. No samples 
were found to comply with the definition for meat juice, nor were 
any peptones of American manufacture examined. The well-known 
German allmmose and peptone powders, somatose and Witte's pep- 
tone, seem to answer the definition of peptones. A class of products 
consisting largely of al])umoses and peptones under the general 
name of "atmid" or steam products is on the market. Another 
class of albumose and peptone preparations is prepared by chemic- 
ally treating lean meat with acid and ])cpsin, by means of whicli all 
the fibrin, albumin, and gelatin are rendered soluble after lieing 
digested in water at a temperature of 100° F. 

In tills connection attention may be called to tlie crab extracts 
which have recently appeared in the German market. Ackei'mann 
and Kutscher" descriV)e and present the analj'sis of an extract jire- 
pared from the flesh of crustaceans. This product has appeared on the 
market in Germany under the names "Krebsextract," "Krebsliut- 
ter," and "Krabbenextract." Extracts of tliis class do not repay 
the outlay necessaiy for their preparation. The lusiial method em- 
ployed in manufacturing a meat extract was used. The nitrogen 
bodies were separated by the Steudel-Kutscher treatment with 
tannin, baryta, and lead. No kreatin or kreatinin was found, but 
an abundance of leucin, tyrosin, arginin, and lysin. Several of tlie 
constituents of this extract have been isolated and identified. Other 
extracts are prepared from fish, shrimps, clams, anchovies, etc., but 
are not of any great commercial im]iortance. 

The various extracts, juices, and powders included in Tables IX 
and X under " Mi-scellaneous preparations" are grouped according 
to tlie following classification: Class I, includes extracts with high 
total kreatinin (approaching 10 per cent) and a total meat base con- 
tent of 40 per cent. The proteose and peptone nitrogen should run 
from .30 to .50 per cent. Pro<lucts in Class II have a proteose and 
peptone nitrogen content above 50 per cent. They are low in both 
kreatinin and meat bases. Class III includes preparations that 
are low in proteose and peptone nitrogen and in kreatinin, but high 
in meat bases. Class I\ includes extracts that are high in insoluble 
and coagulable proteid. The last four extracts are included in the 
fourth class. Extract marked No. 15910 resembles those of Class I 
and the extract marked No. 16037 tho.se of Class II, but in both 
cases tlie insoluble and coagulable proteid figures are high. Sev. 
eral meat powders are included in Table VII. The number of such 

"Zts. Nahr. Gpiuissiu., 1907. ;.>MSO, 010, G13. 



MISCELLANEOUS PREPARATIONS. 25 

products is far less luiinenms llian the solid and fluid extracts. 
The.se products consist largely, if not entirely, uf all)unio.ses and 
peptones 'm addition to some insolultle proteid matter. The amoiint 
of insoluble and coagulable proteids is relatively small in most of 
the samples examined and the balance of the nitrogen is distrilniteil 
between the proteoses, peptones, and meat bases. The relative 
amoimt of these nitrogenous bodies present depends on the method 
of manufacture and extent of the hydration to wliich they are sub- 
jected. The net weights, as well as the retail prices of the extracts 
purchased, are interesting and are gixcn in Tables II, IV and IX. 

Drsrr.Ksiox ni' I{k«i i.ts. 

In several of these pre])arations but a small amount of meat extrac- 
tives or bases is found. The amoimt of kreatin and krcatinin is 
negative in several cases, showing that the products in (|uestion 
were not made by the evaporation of an infusion of meat. The 
total nitrogen is extremely low in a numl)er of instances, falling to 
0.42 per cent in sample 16044. The stinudating value of the aniido 
acids and the nutritive value of the higher forms of nitrogen must 
be exceedingly small in these cases. This same sample (l()(i44) 
contains 91.69 per cent of water and retails for $1 per l)ottle of 477 
grams. Another sample, 1.59.S9, retailing for 60 cents a bottle of 
179 grams, is evidently largely an artilicial product and on aj);ilying 
the method for the determination of organic phosphorus the sanijile 
did not appear to resemble a heef juice or extract. This sani])le 
contains but 2. .36 percent total nitrogen, of which only 8. SI percent 
is in the form of meat bases: krealinin is lacking, the insoluble resi- 
due is relatively large, and alcohol is ])res(>n(. 



26 



MEAT EXTRACTS. 



a, 

5, 



H 

5 

-ft 



■ft 
B 


g 
■c 




.60 
.76 
.50 
.50 

1.00 
.25 
.60 
.60 

1.00 


aj BO 

2; "3 


^O'0t^01-V--<CS,l0l-<NXX0--l000OW'-l 


|sss';.g*^g|5gSgSi^'iSi 




tig 


S!S;£;t;gSf:!SSSSSSS!=S-s5 


-oc. ^....TW-- -H co^a gg 


^«1 


tiKS3S;1SH«S£SS22?SS;g 


p*d ^ ^ (Nw^ 


1 

c 

a 

o 


if 

E 




ss-ssssssssasssBS^" 






tSSSS2SS§SS8SgSSSS5S 
^ ■ .-J r-i oi ■ ■ ,-; " ■ .-I ■ ' ■ T-i po 


c c s; 
x5i 




SSSSJiSSSSSSSSSSSS 




S cd ji C 


^= 


CO 2 g 


3ii 
^11 




ggSS!2SS28SgSt;S5Sg 


r-.{M M^^ ^<n^ 


4S 




S52Sg?^:2S8gS?SSS3S° 


CI CI — (M M —1 CI 


si 




SgSS22H*S2S2S?S§SS 


cc---.-,-^ 


c ce bt— c ;a 




S2§3S§?iSS3Sg?iSS"?3 


-1 j: -a -a "O 




tS: 

»;■" 


S;§8g«5f:!5SSSSgg22S^' 


ifir^^ ccco',c«ocicii-5MO-^cccii' 










r* ^ o -^ «5 ■ --^ o CO irf .5 .-H .-; .-; -fp oi >rf c-i * ' 


1 

8 

S 
S 
s 




IC 




•OiOO 


(j^c-j r-; ■ 'w 


•-< 




^ 


^^^:^S^S22SSSSS 


ggg 


" 




^ 1 o . 

^-§.-l.§ 


^9 


SS^SS3gESS?SS32S5^St2^ 


ci ci ci oi ^ M ^ 






t^C0OO<Nt~C0t-O'->O»0;3.-^00-V=g' 


ocoo wJoi'r^.-H t-^ T-( CO r-H C5 ■ 


■ 6-* 






-^ [^ ^ -qi t^ oi -^ — 1 ci -H ec M « r^ lo 

^ _ ^„ c^ Cl Cl 






t;RgSg-S2fc?!SS88S2SS3S 


a.SgsgSSSiJSSSSgSSK'*'" 




Id 

1^' 


g 


IsliSSii 


iiigiSiii 



NITROGENOUS CONSTITUENTS. 



27 



1 

■fl 

o 
o 

fl 
1 

-5 
o 

o 

E 

2 


Am- 
monia. 


^ Cl ci CO CO 


Meat. 

bases 

other 

than 

kreatin, 

kreati- 

nin, and 

xanthin. 


al 


Xanthin 
leases. 


Per cent. 

2.19 

2.85 

.64 

.78 


Kreatin 
and krc- 
atinin. 


Per cent. 
7.76 
9.07 
7.41 
8. 59 


Total 
meat 
bases. 


Per cent. 
37.44 
34.34 
37.80 
33. 59 


Pep- 
tones. 


Per cent. 
19.90 
11.39 
31.03 
14.00 


Prote- 
oses. 


Per cent. 
34.40 
29.89 
25. 03 
46. 88 


m 


Per cent. 

5. .5(1 

21.53 

2.43 

2.34 


VI 

1 

M 

§ 
£ 
i?. 


-^1 


Per cl. 

0.19 

.19 

.35 

.05 


Meat 

bases 

other 

than 

kreatin, 

kreati- 

nin. and 

xanthin. 


.^ ^ M f- t^ 

fi 6 O) (M 0> 

a. 


a 

l| 


Per cent. 

0.3.5 

.43 

.14 

.03 


■Sid 

S-0-.P 


Per cent. 
1.44 
1.59 
l.Sl 
.34 




Per cent. 
0.93 
0.02 
9.24 
1.34 




Per ct. 
7.38 
4.00 
1,5. 19 
1.13 




Per cl. 
12. 75 
10. .50 
12. 25 
3.75 


Insolu- 
ble and 

coagula- 
ble 

proteids. 


Per cent. 

2.06 

- 7. .56 

1.19 

.19 


Total 
prote- 
ids/' 


Per cl. 
22.19 
22.06 
28. 63 
.5. 07 






1.5911 

1.5963 

15976 

ICWO 



Cl Cl -^ CO c* 



iG r^ Cl CO c; Cl CO ci 



ass 






H ;3 -j: o Cl Cl 



■1 CO Cl o ^ o 



o> cQ'-'la^c: a. c-i ■£> c/j 

lO --5 "^^ -^ -J- .-. r-. ,-, ^ 



'■*A 'A 



OJ » cc r^ Cl 05 X' >o 



oimo) 


f32 


cooco 


cni- 


oc- 


Ot' 


§22ig5S^gS 






CO —< 



«CI 

^ CO 

■^lO 



coo 

.-H Cl 

Cl ci 



crci 

o o 



5 =-■ ^ 

COCl ^ C3 



■^ COCI o 




CIGOOO 
C-i TT gC' ■^ 

^OQi>i 
■^ lO o r— 



S2g2 


1" CO 


-H to 


:^^S2 


oo 


'*CI 


r- CO CI c) 

CC — QCCO 


QC--i 


^■;:= 



O r- cr. -H 
t-i coco 'a' 
o ooo 

.n '.a 3 o 



28 meat extracts. 

Methods of analysis and their discussion. 

(_)iio of tlif i^rcat olistaclcs in the way "f a tliorc)u>;li uiul careful 
.study of jnoteids is the unsatisfactory condition of the analytical 
methods. Many of the variations in reaulfs wliich have apjieared 
are undoul)tedly (kie' to faidty methods. Another serious source of 
error in tliis line of woric lies in the fact that different methods are 
used by different analysts and the results are not comparable. For 
instance, copper oxid, phosphotungstic acid, tannic acid and salt, and 
other reagents, are used by various workers to precipitate the higher 
amido bodies and separate them from the simpler amido bodies. 
That the precipitating power of these reagents is not the same is well 
known. For determining acid and alkali albumins, insoluble proteid, 
and coagulable proteid, the methods give only ajjprnxinuite results, 
those for the determination of several of the individual bmlies, such 
as kreatin, kreatinin, and ammonia, bein'g in a much more satis- 
factory condition. 

PREPAKATION OF .SAMPLE. 

In the case of li(juid and scmilicjuid ])rc])arations the bottle should 
be thoroughly shaken and great care taken to see that the solution is 
complete. Pasty and solid extracts or powders should be removed 
from the container and thoroughly mixed before sampling. A very 
convenient method is to dissolve a weighed sample in a measured 
quantity of water and run tiiis out of a burette as needed. This 
solution siiould be kept cold and the determinations started without 
delay. 

MOISTITRE. 

Moisture was determined in tiie various j)re])arations examined by 
drying the sample over night in a water-jacketed drying oven. In 
the case of solid meat extracts approximately 'i grams of the sample 
were used, for iluid extracts, 10 to 12 grams, and for meat powilers, 2 
gi'ams. 

ASH. 

The ash content of the commercial samples is seen to be surju'isingly 
iiigii in many cases. (See Tables II, IV, and IX.) This is du(> to the 
fact that sodium chlorid is present in meat extracts in varying and 
often excessive quantities. Especial attention is called to the large 
percentage of sodium chlorid ju'escnt in several of the sam|des exam- 
ined. The figures reported in the tables are obtained by calculating 
the total cidorin to sodium chlorid. 

The ash was tletermined by the olHcjal metliod " and the so(Hum 
cidorid in the ash by the following ])rocedure: 

Dissolve the ash sample with nitric acid and make iiji In Vdliimi' in a 20l)-cc llasl^. 
Use 20 per cent, or any convenient ali(iuot, for titration u illi sulpho-cyanid according 
to the Vdlhard method. 



«U. S. Dept. Agr., Burean of Chemistry, Bui. 107, p. 38. 



METIIUDS OF ANALYSIS. 



29 



I'rl-i-rnt. 

.. n.-.M) 



A small amount of soiliuiu chlorid is ])ri'sent in nu'at, anil as much 
as 12 per cent is permitted by the tentative standard for meat extract, 
but the presence of 25 to W per cent is excessive and should i)e 
regarded as an adulteration. 

From 0.8 to l.S per cent of meat is mineral matter, and calculated 
to water-free substance this amounts to from 2.3 to 7. -5 per cent . The 
average composition of the ash of meat, according to Konig," is as 
follows: 

r.T riMlt. 

Pnlat^siuin :57.()4 

Sodium ID.M 

Calcium :-'.-)2 

M:i<;iu'sium 'A.'S.i 

O.Kid nf irnn O.-t-l 

Jolly'' gives some vei'V interesting ligures sli 
binations of ])hos])horic acid found in the muscles and tendons of 
calves and oxen, and the nu'tabolism of the various mineral sails 
is fully discussed ])v Albu and Neul>ei-g.' The analyses of the ash of 
several samples of meat juic(^ ])re|)ari'd in (he laixiratory arei^iven in 
Table XI. 



T'hci.^plinric acid. . _ 

Sidpliuric aci<l I). 



(_'lili)riii. 
Silica... 



I.(;(l 



tl 



U' various com- 



Tajsle XI. 



.\iii!his(s nj ash iij mint juia's. 





Substance. 


Chlorin 

as 
sodium 
chlorid. 


Composition of salt-free ash. 


Serial 

No. 


Insol- 
uble 
matter. 


Cal- 
cium 
oxid. 


Mag- 
nesium 
oxid. 


Potas- 
sium 
oxid. 


Resid- 
ual so- 
dium 
oxid. 


Sul- 
phur 

tri- 
oxid. 


rhos- 

plioric 
acid 


K7m 
197117 


.luice from l.ieef chuck at r,n°r 
Juice pressed from sirloin 
steak . 


Pent. 
12.37 

8. .'ill 

10.20 

12. 15 

13-43 


PrTcl. 
0. 4.1 

0. "ill 

1.02 

1.00 

1. 119 


Perct. 

0. .V.l 

0. 911 
Trace. 
Trace. 

Trace. 


Per It. 
0. 10 

Trace. 

Trace. 

0. 49 

0.37 


Pern. 
47. 8.1 

4.5. 07 

49.77 

47.30 

51.58 


Per It. 

r,. 91 

2 71 
4.04 
8.03 

9. 40 


Pent. 
3. 37 

1..1I1 

0. 00 

n. 74 

1. 91 


Pent. 
33. 22 

37. 12 


19785 
19780 
19787 


Juice extracted from sirloin 

steak by cold pressure 

Juice extracted Ironi beef 

chuck by cold pressure 

Juice extracted from l)eef 

chuck after 6 hours at 60° 

to 100° C 


33. 74 
29, .Ml 

34. 20 









The most striking point in the analysis of the ash of meat extracts 
is the large amount of potash salts present, practically one-half of 
the salt-free (XaCl-free) ash being composed of potassium oxid. 
The amount of phosphoric aciiK is also high, amounting to fully 
one-third of the salt-free ash. The percentage of phosphoric acid 
given in the table may be low, as part of the organic phosphoric acid 
is volatile especially if the ash be heated to a very high temperature. 
The other constituents of the ash of meat juice are oxid of iron, 



" ('licmi.'iclie Zusammensetzan^' ilcr mcnsrhlirlicii Xaliiuni,'.-;- iiiid (,ienu.ssmitlpl. 
1.SS9. :5rd cd., 7: 23(5. 

''('umpi. rend., 1S7!), ,s'9:95S. 

(■Mineral Stoffwechsel, Berlin, 190G. 

d Tlie iirovisional volumetric method was used — U. S. Dept. Agr., liuieau ni ('liem- 
istiy, Hul. 107, p. 16. 



30 



MEAT EXTRACTS. 



calcium, niatcnesiuni, anil sodium. Phd.spliates anil sulphates of cal- 
cium anil potassium, orsjanic sulphur, anil a small amoimt of insoluble 
matter, principally silica, are also present. 

In Table XII fii^ures are <j;iven showing the composition of the ash 
of various meat extracts and miscellaneous preparations. As the 
percentage of sodium chlorid shown in Table XII is nuich greater than 
that present in the natural meat juice, the figures for the salt-free 
ash are correspondingly lower. The amount of insoluble nuitter is 
surprisingly high in several cases and it appears that some insoluble 
substance must have been added. For comparison the following 
results are quoted from Konig," showing the average composition of 
the ash of meat extracts: 

I'or cent. 

Potassium 42. 2G 

Sodium 12.74 

Calcium... 0. G2 

Magnesium 3. 15 

Oxid of iron 0.28 

Results of the aiudysis of the ash of meat peptones are also given. 
Konig states that the salts, especially the potash salts present in the 
ash of meat extracts, are valuable on account of their action on the 
nervous system. 

T.\BLE XII. — Anatijscs <>/ liir iixli of iiHiit cxlmi-ts awl inisrilhnuoiis prfjiiirtilions. 



Phosphoric arid 
Sulphuric acid. 

Silica 

Cliloi'in 



I'rr ciMlt. 

. . ■■',(). .Ml 

. . 2. o:i 

. . 0. ,Sl 



18152.. 
18159.. 
18101.. 
18434.. 
18435.. 
18563.. 
185S4.. 
18023.. 
18624.. 
19398.. 
19399. . 
19401.. 
19707.. 
19818.. 
184IX).. 
18033.. 
18036. . 
19458.. 
19400.- 
194C5. . 
19467. - 
18629.. 
18635. . 
18637. . 
19817. . 
18877. . 



Chlo- 
rin as 
sodium 
chlo- 
rid. 



Per 

rrnt. 

39.78 

40.85 

«3. 47 

41. 39 

S2. 13 

34.22 

53.23 

75.27 

33.64 

32.65 

46. 65 

37. 61 

12.78 

12. 24 

12.21 

42.34 

22.93 

30.88 

12. 21 

49.97 

57.17 

47.33 

54. 80 

53.98 

48.02 

39.48 



Composition of salt-free ash. 



Insol- 
uble 
mat- 
ter. 



Pit 
cent. 
0.42 



4. 06 
.07 
1.43 
1.02 


.74 

8.02 

9.05 

2.74 

9.97 

3.01 

29.38 

6.38 

1.70 

.61 

29.38 

5.74 



Ferric 
oxid. 



Prr 
eeiU. 



1 


35 


11 


.35 


17 


28 




05 


3.46 


14 


11 



■ "(V)" 



Cal- 
cium 
oxid. 



Per 

cent. 

0.27 

Trace. 

1.42 

Trace. 

1.02 

Trace. 

.20 

Trace. 

Trace. 

.40 

Trace. 

3.72 

Trace. 

Trace. 

.32 

7.80 

Trace. 

9.33 

.32 

.04 

Trace. 

.59 

Trace. 

Trace. 

Trace. 

Trace. 



Mag- 
nesium 
oxid 



Per 
cent. 
0.35 

Trace. 
.47 
.90 

Trace. 
.17 
.41 

Trace. 

Trace. 
.5(i 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

16.82 

.18 

.95 

Trace. 
.54 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 
.17 



Potas- 
sium 
oxid. 



Per 
cent. 
53.44 
40.81 
50.31 
40.92 
27.59 
45.53 
64.70 
40.30 
.50.51 
51. 30 
49.07 
39.01 
42. S5 
41.21 
27.59 
3.17 
43.88 
30.22 
27.59 
45.75 
47.02 
46 82 
39.00 
49.03 
32. 42 
34.90 



Resid- 
ual so- 
dium 
oxid. 



Per 
cent. 
7.31 
6 20 
6.52 
13.97 



8.47 
6 37 



in. 02 
4.08 
5.27 

13. 24 

10. 40 
9.04 
0.99 
3.40 
4. 76 
6.03 
0.99 
4.94 
5.23 

18. 30 
9.09 

18.99 
9. 22 
7.72 



Sul- 
phur 
tri- 
oxid. 



Per 

cent. 
5.50 

11.19 
8.13 
4.09 

21. 94 
2.19 
2. 40 



3.47 
2. .55 
5.44 

1,5. 18 
2. 59 
2.90 
1.81 

10.30 
3.48 
5.30 
1.81 
3.70 

10.60 
2.50 
4.51 
2.33 
6. 25 
3.27 



Phos- 
phoric 
acid 
(PiOi). 



Per 
cent. 
23. 26 
25. 60 
24. 50 
25.25 
23. 84 

23. 99 
30. 08 

29. 40 
22. 30 

24. 29 
27. 09 
20. 05 
22. 70 
20.75 
26.37 

.69 
28.31 
37.53 
20.37 
32.18 
29.65 
27.51 
23.98 

30. 05 
24.53 
16 Sfi 



Alkalin- 
ity (N/10 
hydro- 
chloric 
acid). 



cc per IW 
gramfi. 
79,71 
(iO. 80 
S.5. 90 
2(i. 10 
,9.80 



70. 13 
03. 49 
£0. 47 


OS. 76 

5.5.' 04 

43.00 


65. 91 
107. 64 
43.06 






75.06 
79.10 
33.31 



a Loc. Cit, 



d Present in small amount. 



c Present, 



METHODS OF ANALYSIS. 31 

SEPAKATION OF ORGANIC AM) IXOR(iA\lC PIIOSPHOItUS. 

Tlie 10:1 ratio of total phosphoric acid to organic phospiioric acid 
suggested by Siegfried and Singewald " is not constant. This nietliod 
should be further investigatetl before applying it to all extracts anil 
food products in general. The high inorganic phosphoric acid con- 
tent in some cases might be explaine(l by tiie fact that jiliospliates 
may have been added, but \vc should hardly expect this in the case 
of organic phosphorus. 

The method of Siegfried and Singewald for the separation of the 
organic from the inorganic jihosphorus was aj)j)lie(l to meat extracts 
m the following manner: 

Dissolve an amount of the original sani])le corresponding to Id 
grams of the water-free material in water in a 'MH) <-i- flask. A<ld ."lO n- 
of barium chlorid (10 per cent solution) and 10 cc of auimonia (10 
per cent solution). Make the solution up to the mark and thoroughly 
shake. Allow to stand and emi)loy an aliquot of '250 <•(• of the filtrate 
for the estimation of phosphorus by the peroxitl method to obtain 
the amount of phosphorus present in organic form. Tliis liguri' sub- 
tracted from the amount of total ])hosphorus gives the amount of 
phosphorus in the inorganic form. The accuracy of the m(>thod is 
questionable as the filtrate in the majority of cases was cloudy, and 
sometimes the slow filtration renders the method extrtMucly te(lious. 

Aciorrv. 

In the average solid or pasty extract the lactic acid content varies 
from 4 to S per cent, and, as a rule, the extract showing the highest 
jihosphoric acid content likewise sliows the highest acidity. This is 
undoul)tedly due to the fact that some of the phosphoric acid is in 
the form of dihydrogen or acid phosphate, although the cliaracter of 
the acidity has not been deiinitely determined. 

The method employcHl for determining acidity consisted in adding 
tenth-normal sodium hydroxid to a dilute solution of (he meat 
extract in water luitil a drop remo\(Ml by means of a small capillary 
tube and tested oil a piece of litmus paper gives a- neutral reaction. 
The results are expressed in v\\]nr centimeters of tenth-normal 
sodimn hydroxid, also as per cent of lactic acid ])reseut. It is recog- 
nized that the acidity of meat extra(-ts is due to various causes, l)ut 
lactic acid is the predominating acid, and the results for acidity are 
usually expressed in the case of such products as per cent of lactic 
acid. ' (See Tables I, III, and IX.) 



«Zts. Xahr. (lenussra., 1905, lii:F,2l, 



32 MEAT EXTliACTS. 

NITROGENOUS BODIES. 

(.'lasses of Nitkogenous Constituents and General Methods (jf Separation. 

It is believed that the proteids are made up of molecules of extreme 
complexity — hundreds of atoms of carbon, hydrogen, oxygen, and 
nitrogen — but the arrangement of these atoms and their number 
have not been tlefinitely determined. Various proteid substances are 
spoken of, for example, albumins and peptones, as pure chemical 
sidistances, but it is impossible at present to prepare two specimens 
of egg albumin exactly alike, and in the case of peptones even more 
difliculty is encountered. Because certain nitrogenous bodies give 
color reactions that are alike antl exhibit a few points in common, 
they are grouped together umler a definite term. It is not surpris- 
ing, therefore, that the methods for the separation of nitrogenous 
bocUes are far from satisfactory in many cases. 

Professor Mallet" says the following classes of the nitrogenous 
constituents of food arc commonly recognized as reipiiring separate 
consideration : 

1. I'roteids proper (liy somr' lalled alluuiiiiiciicli^i, and their cldsely }('laU'(i deriva- 
tives, the proteuses and pei)tones. 

2. Gelatinoids or collageiis, and allied .sulwtanees immediately deri\ed injru them, 
sueh as gelatin, ehondrin, ete. 

3. Simpler amids, amido-acids, and allieil sub^taiiees, such as the asparagiu, glu- 
tamin, etc., of vegetable materials, and the "flesh bases'' (kreat'iii, Icreatinin, etc.) 
of animal origin. 

4. Alkaloids, or anunediUe coniiiounds of well determined liasic character. 

5. Ammonia and its salts. 
(!. Nitrates. 

To these, no doubt, should be added lecithin and analogous sidj- 
stances containing nitrogen, but closely allied to the fats. 

The average nitrogen content of the pasty or solid extracts usually 
varies from 6 to 9 i)er cent. The nitrogen in the so-called meat juices 
is subject to much greater lluctuation, depending largely on the con- 
tent of solids. Although a high nitrogen content is not a guarantee 
of the character or mode of manufacture of an extract, an average 
nitrogen content is desirable. 

All nitrogen determinations were made by T. C. Trescot. 

Several new determinations were applied to the analysis of meat 
])roducts. These include the separation and estimation of the meat 
bases by a modification of the Schjerning tannin-salt method,'' the 
determination of kreatin and kreatinin by the colorimetric method of 
Folin,'^ the determination of xanthin bases by the method of Schitten- 
helin,'' the estimation of ammonia by the magnesium oxid method,'' 

" U. S. Dept. of Agi-., Bureau of Chemistry, Bui. .54, page 7. 

bj. Amer. Chem. Soc., 1906, 7„':1485. 

cZts. physiol. Chem., 1904, .il:223. 

dlJ. S. Dept. Agr., Bureau of Chemistry, Bui. 90, page 129. 

""U. S. Dept. Agr., Bureau of Chemistry, Bui. 107, page 9. 



METHODS (IF ANALYSIS. 33 

the iletenninatiiin of total plmsjiliorus by tlie peroxiil method," anil 
the separation of the ori;;anic from the inorganic phosphorus by the 
method of Sie<;fried and Singewald/' described under ash. Sodium 
clilorid was estimated by tlie Volhard methotl.'' 

The methods of the Association of Ofhcial Agricidtiiral Chemists 
were used in most cases.'' For tlie determination of total nitrojien, 
total meat bases, xanthin bases, and insoluble and coagulable pro- 
teids alicjuots of one solution of the sample were used. The pep- 
tones were determined by the tannin-salt jnethod' and the kreatinin-' 
bj' a modification of Folin's meth(jd (page '.]'.)). 

Many reagents have been used to separate the meat bases from the 
nitrogenous bodies of larger molecular weiglit. Phosphotungstic 
acid has been more widely employed than any of the otiiers, but is 
known to precipitate many of the diamido acids,' and its jiower to 
precipitate completely the peptones'' is not established. Mallet' 
states that the use of phospliotungstic acid as. a precipitant, fol- 
lowed by washing the precipitate with hot water, seems to effect a 
separation of all the simpler amidic sul:)stances from the ])roteids and 
proteid-like bodies, excepting only the ])eptones. Mallet cpiotes 
authority to show that the peptones are precipitated by tannic acid. 
The method was tried in tlie present investigation, but was discarded. 
Bromin has been suggested by Allen and Searle' as a reagent for 
separating the higher amido bodies from the lower aniido acids, but it 
has Ijcen found by Schjerning' and others to ])e unrelial)le. That 
tlie tannin-salt reagent makes an absolute separation is not claimed, 
but it seems to lie the best at jiresent available. 

Ix.SUIABLE .\MI ('c)AGULABLE I'UMTKIIiS. 

In Table XIII figures are given showing the amount of nitrogen 
present in the insoluble form as distinguished from that present in the 
coagulable form. This separation was made on seven extracts in- 
cluded in Table VH (miscellaneous preparations), which showed high 
coagulable nitrogen tigurea. The i)rovisional methoils ' of the Asso- 

aj. .\mer. Cheni. Soc, 1904, ^'6:1108. 

f-Zts. Xahr. Genussm., 1905,70:521. 

cLiebig's Annalen. 1878, 190: 1. 

<'r. S. Dept. Agr.. Bureau of Clienii.<5tn,', Bui. 107. 

< r. S. Dopt. Agi-., Bureau ni Ciiemistiy, Bui. 99, p. 182. 

-' .\11 kreatinin figiires refer to kreatinin and krealin estinialcil as kreatinin alter 
dehydration. 

Sllamniarsteu, Physiological Chemistry, 1904, ]i. 8(1. 

'iU. S. Di-pt. Agr., Bureau of Chemistn-, Bui. 73, p. 92. 

' U. .s. Dept. Agr., Bureau of Chemistry, Bui. 54, p. 21. 

7 Analyst. 1897, ^:i:2bS. 

<■ Zts. anal. Cliem., 1900. .i'</:.545. U. S. Dept. Agr.. Bureau of Chemistry. Bui. 81. 
p. 101, 

' r. S. Dept. Agr.. Bureau of Chemistry, Bui. 107, p. 115. 

43689— Bull. 114— OS 3 



34 



MEAT EXTRACTS. 



ciation of Official Ao;riciiltural Chemists for meat fiber ami coai^ulable 
proteids in meat extracts were followed. 

Tlie amount of insoluble material in several instances is extremely 
large and the name "extract" hardly applies to such products. The 
amount of coagulable proteid in sample Xo. 178S2 is ver\' high. No 
insoluble material should be present in a properly prepared extract. 
As noted under meat juice, however, the coagulable proteid is the 
characteristic form of nitrogen for such products. Meat extracts, 
both the solid and liquid, contain some coagulable proteid. 

Table XIII. — Separation of insoluble and coagulable nitrogen. 





Nitrogen as 




Expressed in terms 






Serial 

No. 




of total nitrogen. 








Insol- 


Coagu- 


Insol- 


Coagu- 


Remarks. 






Total. 


uble 


lable 


uble 


lable 










proteid. 


proteid. 


proteid. 


proteid. 








Per cent. 


Per cent. 


Per cent.. 


Per cent. 


Per cent. 






17879 


4 57 


1. l(i 


0.141 


25.38 


3.09 


Same lirand as 15910, Table VI. 




17880 


8.505 


3.15 


.015 


37.04 


.17 


Same brand as 15909, Table VI. 




17881 


2.015 


.312 


.619 


15.48 


30.72 


Same lirand as 16943, Table VI. 




17882 


2. 4.3S 


.013 


2. 32 


.53 


95.28 


Same brand as 15989. Tal)le VI. 




17884 


3.22 


1.66 


.02 


51. 55 


.62 


Same lirand as 16037, Table VI. 




17885 


6.315 


. 202 


.029 


3.19 


.46 


Made \>v company manufacturing l(i041. 














Talile VI. but an entirely 


dillerent 














product, as stated on laliel. 




17887 


5.81 


1.13 


.021 


19.45 


.36 


Same brand as 15963, Table VI. 





Protecses .\xd Peptones. 

The following tentative standard for peptones has been framed by 
the standards committee: 

Peptones are products jjreparcd by the digesti(_)n uf proteid material liy means of 
enzymes or otherwise, and contain not less than ninety (90) per cent of proteoses 
and peptones. 

The proteoses and peptones are nitrogenous bodies of smaller 
molecular weight and greater solubility and diffusibility than the 
albumins. They are prepared fi-oin the albumins by the process of 
hydration. The peptones are lielow the proteoses in the process of 
hydrolysis. The distinction between the proteoses and peptones 
usually considered is that made by Kiihne," who defined the pro- 
teoses as nitrogenous bodies precipitated by ammonium sulphate, 
while the peptones are not proiijMtated by this reagent. These two 
bodies also differ in solubility and as to certain chemical reactions. 

The zinc sulphate method'' was employed for the determination 
of the proteo,ses. The peptones were precipitated together with the 
proteoses by the tannin-salt reagenf and the peptone figures ob- 
tained bv difference. 



aZts. Biol., 1S8C, -'2;-12;?. 

6U. S. Dept. Agr.. Bureau of Chemistry. Bui. 107, p. 11.5. 

cU. S. Dept. .\gr., Bureau of Chemistry, Bui. !l!l. p. 1,S2. 



METHODS OF ANALYSIS. 35 

In regard to the nutritive value of the alhuinoses ami peptones 
much uncertainty exists, but many investigators, as Munk," Deiters, ^ 
Zuntz,"" Pollitzer/ and others, have showai that pure aibumoses and 
peptones can replace proteid matter of ecjuivalent nitrogen content. 

The nature of the proteoses, as precipitated by saturating a sam- 
ple of Liebig's meat extract witli zinc sulphate, was lately investi- 
gated bj' Micko,*" who applie(l the Fisclu'r ester method to the pro- 
teoses. He identified the following amido bodies by tliis method: 
Glj'cocoli, leucin, isoleucin, alanin, amido valerianic acid, prolin (race- 
mic and active), asparaginic acid (ra<'emic and dextrorotatory), glu- 
taminic acid anhydrid, and phenylalanin. Xo xanthin or kreatin 
was found in the proteose precipitate. 

Gelatin, 
dexek.ki, iiisitrsion. 

The addition of gelatin to meat preparations has been practiced 
in the past. By this means the manufacturer increased or main- 
tained a certain nitrogen content, but supplied the nitrogen in a 
form lacking in stimulating effect and probably in nutritive v^alue. 
The buyer was consequently deprived of the characteristic essen- 
tials of a true meat product, although the nitrogen content was 
relatively high. In many cases only a small proportion of the added 
gelatin existed in the extract as sucli, as it was converted bj' a grad- 
ual process of hydration into gelatoses antl gelatin peptones. Wliile 
the methods for the separation of gelatin from proteid matter are 
far from satisfactory, it is a nnicli simpler process than the detec- 
tion of gelatoses and gelatin peptones and their separation from tiie 
idbumoses and peptones, no satisfactory method for the separation 
of these bodies being known. 

Some gelatin may be fornieil in the preparation of a high-grade 
extract of meat, although with proper j)recautions thei-e should be 
practically nt)ne present. When a .sufficient amount of gelatin is 
present it is readily detected by the setting (qualities of the extract 
after warming. The power of gelatinizing is only posses.sed by unal- 
tered gelatin; its dissociation products do not have this power. 

Micko-* has recently studied the gelatin cleavage products and 
finds that practically the same liodies are formed on hydrolysis as in 
the case of the aibumoses. In both cases glycocoU predominates. 
This investigator states that no gelatin is jjresent in Liebig's extract 



"Therap. Monatsh., June, 1888. Deulsc'he mcd. Wochcnschr.. 18S9. No. 

fi Von Noordcn's Bpilrage zuv Lehre ■\iini StnflVcchsol. 18!I2. p. 47. 

f .Vrch. gesam. Phy.siol., 1SS.5, ■17:'M3. 

'ilhid., p. 301. 

f Zts. Nahr. Gcnussm.. 1907. ;.i:2-j3. 

/Ibid., p. 284. 



36 MEAT EXTRACTS. 

but tlie soluble funns (glutiu and gelatoses) are present, l)eini; forineil 
by aetion of the lactic acid on the gelatin. 

The following tentative standard has been framed by the fond 
standards committee: 

Gelatin (edible gelatin) is the puritied, ilricil. iiioilnnius i)r(Hluc-t of the hydrnlysis. liy 
treatment with Ijoiling water, of certain tissues, as skin, hgaments. and hone.s, from 
sound animals, and contains not more than two (2) per cent of ash and not less than 
fifteen (15 1 per cent of nitrogen. 

i:.\rEI!IMEN'T.\L WORK UN .METHODS. 

Experiments were made to test tlie foUnwing gelatin methods: 

(1) the Stutzer ice-water alcohol method," modified by Bigelow;'' 

(2) theBeckmann' formaldehyde method: (3) the triclilor-acetic-acid 
method of Obermayer. '' 

The gelatin used in these experiments was a product of good 
quality used in ])repariiig culture media. With Millon's reagent it 
gave a faint pink reaction in the cold, and upon heating a red color 
developed, showing some proteid matter was present. This reaction 
shows the presence of tyrosin, and as pure gelatin contain.s no tyrosin, 
a small amount of proteitl must have been present as an impurity. 
The biuret test gave a faint reaction with the gelatin solution. 

The solution of gelatoses and gelatin peptones used was prepared 
by treating some of the gelatin with weak (3 or 4 ])er cent) hydro- 
chloric acid for I'oiu- days on the steam bath. This solution also 
gave the Millon and biuret tests. Neither the gelatin nor gelatose 
solutions showed signs of gelatinizing. The former was of 1.14 per 
cent and the latter of 0.64 per cent strength. 

The modified Stutzer method gives, in the case of pure gelatin 
solutions, a rough approximation of the amount present, the result,s 
showing that about 84 per cent are recovei'ed. With a solution of 
gelatoses and gelatin peptones, this methoil gives about 3.6 per cent 
of the nitrogen present as gelatin nitrogen. This may be due to a 
trace of gelatin in the gelatose solution. In the case of Witte's pep- 
tone 19 per cent of the total nitrogen aj^jiears as gelatin nitrogen 
according to the modified Stutzer method. It seems that the abso- 
lute alcohol precipitates a portion of the albumoses present in AVitte's 
peptone. In the case of the meat extract used, 3.7 per cent of the 
nitrogen is estimated as gelatin nitrogen by this method. Mixtures 
of gelatin with gelatoses, Witte's jjeptone, and meat extract were 
made in various combinations; also mixtures of the meat extract, 
Witte's peptone, and gelatose without gelatin. The results for gela- 

aZts. anal. Chem., 1895, 34:568. 

l\J. S. Dopt. Agr., Bureau of Chemistry, Bui. 107, p. 110. 

'Analyst, 1895, 20:44. 

d Zts. anal. Chem., IS'JU, l"J : 114. 



METHODS dl' ANALYSIS. 37 

tin were very irregular and iiiaccur'ali', and in all cases (inly a jxirtion 
i)f the gelatin added was reenvered. It is evident that the ]iresence 
of alhunioses and ])epf ones, as well as of geiatoses and gelatin jieptones, 
tends to dissolve tiie gelatin and give low results by this method. 

The BeckinaiHi formaldehyde method," together with some com- 
ments thereon, reads as follows: 

A method fur the estinuiJinn nf m-latin in meal extracts is liascd ii|"iii llic Ilui that 
fdruiaUlehydf cniiiliiiies with it to fnriu a iinufiisilile and insuhilili' cdmpuund — 
fornialiii-gelatiii. In order to render insohiiile I srrani of i,'elalin dissuUi'd in water 
abo\it two drops of the 10 ]ier cent .sohition in water of fornuddehydc ifornialim are 
added. The quantitj' re(|uired is so trirtinj; that its wei,t;ht may lie nei,dected. 

The presence of mucli free acid hinders the reaction, whicli. howe\er, tal<es jihtce 
perfectly well in a slightly alkaline solution. * * * if furniic or acetic acid lie 
present, either too little precipitate is obtained or none at all. "' * * Solul)!e 
egg-albumin and serum alljumiu left residues on niixiuLr wiih formalin. " " 

Merck's dry peptone was found to be completely soluble in the presenc'e of formalin, 
and by this means gelatin and alliumin could be easily separated from peptone. * * * 

In determining whether a meat extract I'ontains gelatin, the albumin is e>rimated 
in an ali(iuot part of a watery solution by means of acid. .\no(hcr portion is treated 
with formalin, steamed on the water bath, and, after l)oiling for a short time with 
water, the residue is collected in a Gooch crucible, dried at 11111° ('., anil uci<;hcd. 
After subtracting the amount of albumin |irevionsly foitnd. this gives the gelatin. 
The pciitoiie, etc., in the liltrate can be ])recipitated in the usual way. The method 
will be of use in milk analysis for detecliny adulteialion with an enndsion i.f Liclatin 
and fat. 

The results obtained by this methoil were not salisfaclorv, and eon- 
firm the results obtained by Stutzer. .Vll of the solutions were 
filtered hot. The gelatin does not seem to form tin insoluble formtiiin- 
gelatin as described by Beckntaim and the gelatin results were 
extremely low. In the case of meat extract and \Vitti>'s pejitone, 
some nitrogenous matter was precipitated by the formaldehyde, the 
latter giving quite a large preci])itate. When the gelatose solution 
was useil, practically no precipitate was obtaiiieil. ( )n mixtures of 
these various substances, eitlier alone or in the presence of gelatin, 
only incomplete results were obtaine(l. 

Obermayer agrees with liaal>e'' in stating that trichloracetic acid 
will precipitate albumin and albumin peptones and thus affords a 
separation from other ])ept()nes, such as gelatin pejjtones, which are 
only precipitated by this reagent in concentrated solution. 

The trichlor-acetic-acid method for precipitating gelatin as t)utlined 
l)y Obermayer is briefly as follows: 

Precipitate the solution with an excess of trichlor-acetic acid, and 
wash the precipitate with dilute sul])huric or hydrochloric acid. 
Thoroughly extract the precipitate with alcohol, then with ether, 
dry and weigh the precipitate. According to Obermayer, the albu- 

" Report of ThirteeiUh .\ssembly of Bavarian Chemists, 1S04. pp. lS-20. 
i'Zts. anal. Chem., 1S82. ^'1 : :iO:^. 



38 MEAT EXTRACTS. 

mins and gelatin, as well as the albumin and gelatin peptones, are 
precipitated by this reagent. In an excess of the reagent the albumin 
peptones are soluble, while the gelatin peptones are not. 

A 10 per cent solution of trichloracetic acid was prepared and its 
action tested on the following nitrogenous bodies: (1) Gelatin; (2) 
a mixture of gelatoses and gelatin peptones; (3) Witte's peptone 
(albumose and peptone preparation) ; (4) meat extract. The results 
of the test are as follows: 

In the case of the gelatin sample ten drops of the reagent gave a 
slight precipitate, while the other three nitrogenous substances exam- 
ined gave no precipitate. An excess of the reagent gave a heavy 
white precipitate with gelatin and Witte's peptone, a smaller pre- 
cipitate in the case of the meat extract (the reaction being obscured 
by the ilark color of the solution), while the gelatose solution showed 
only a sUght turbidity. 

It is evident from these results that trichloracetic acid does not pre- 
cipitate the gelatoses, neither when a small amount nor when an 
excess of the reagent is used. The gelatoses are precipitated by the 
tannin salt reagent and it is possible that a method for estimating the 
gelatoses may be worked out on the basis of the trichloracetic acid 

reagent. 

ToTAi. Meat Ha.ses. 

The meat bases contain from 4t) to 60 per cent of the nitrogen in 
solid meat extracts, as is shown in Table III. In one of the poorest 
extracts examined, but 3.82 per cent of the total nitrogen is present 
in this form. 

The meat bases are (hvided into two general classes, the mono- and 
the di-amido acids. By the method of analysis employed, the meat 
bases are found in the liltrate from the tannin-salt ])recipitate. 
Some of the meat bases, for example, kreatin and kreatinin, and the 
hexon and xanthin bases are well defined chemical bodies that have 
been isolated and analyzed, but a considerable number of the nitro- 
genous bodies classed as total meat bases are of unknown constitution 
and are classed as imdetermined nitrogenous matter. 

Many new bodies have been foiuul in meat extract in recent years. 
Kutscher" has recently found the following nitrogenous bodies: 
Ignotin, methyl guanidin, carnonuiscarin, neosin, novain, and oblitin. 
Krimberg'' has demonstrated the presence of carnosin, carnatin, 
and methyl guanidin in flesh. Micko"^ applied Fischer's ester method 
to Liebig's extract anil foiuid alanin, leucin, and glycocoll in abund- 
ance. Xo amido valeric acid was found, and most of the aniido acids 
were left in a sirupy mass. 



«Zts. Nahr. Genussm., 1905, .?0:528. 
6Zts. physiol. Chem., 1900, 4S •.4i2. 
c Zts. Nahr. Genussm., 1902, 5 :193. 



METHODS OF ANALYSIS. 39 

Interniediad' Ix'tweea the pejjtoiu's ami the aniidu acids is a 
class of substances, recently described by Fischer," called peptids, 
which are divided into two classes, the dipeptids and the p()ly])ep- 
tids. The importance of Fischer's work can not be overestimated, 
as a lieginning has thus been made in the imjxirtant prolilem of deter- 
mininji' the construction of the proteid molecule. 

KrEATIN .\NI> KliEATININ. 
AI'PLK'ATIOX OF KREATININ' TEST TO MEAT EXTRACTS. 

Kreatin and kreatiuin are two amido bodies which characterize 
meat and therefore the\' are natural and essential constituents of 
meat preparations. The other meat, bases are important constitu- 
ents of an extract of beef, but occur in smaller amounts. 

As kreatin is the princijial amido botly found in meat, we expect 
to iind it, together with kreatinin, its dehydrated form, in still larger 
cjuantities in meat extracts. In several cases in which the extract 
acted suspiciously, no kreatin was found, and grave doubts exist as to 
the source of such products. True meat t^xtracts give high kreatin 
and kreatinin results, as well as high figures for meat bases. The 
estimation of the kreatiii and kreatinin is, therefore, a very important 
determination and of great value in determining artificial and imita- 
tion meat and yeast products, and in establishing the .source and 
purity of an extract of meat. 

The determination of kreatin and kreatinin was carried out a.s fol- 
lows: Use an ali(|Uot of the filtrate from the insolul)le and coagulable 
proteid determination, the amount depending on the character of 
the extract.'' The ali(jUot must contain sufficient total kreatinin, 
after dehydration of the kn^atin to kreatinin, to give a reading not 
far from S° on the scale of the Dubosc colorimeter after applying the 
colorimetric method as outlined by Folin'' for tlie estimation of krea- 
tinin in the urine. Heat this alicpiot with 5 cc of half-normal hvdro- 
chloric acid for three and a half hours on a steam bath under a rellux 
condenser. Neutralize the hydrochloric acid by the atldition of .5 cc 
of half-normal sodium hydroxiil, then add 1.5 cc of a saturated 
picric acid solution, and 5 cc of 10 per cent sodium hydroxid. 
Shake the solution and allow it to stand for live minutes; make u]) 
to 500 cc and compare the color with a half-normal solution of potas- 
sium bichromate in the Dubosc colorimeter. The half-normal 
bichromate solution when the scale is set at 8° corresponds to 10 mg 
of kreatinin and from this figure the amount of kreatinin in the ali- 
quot is readily calculated. 

" UntiTsurh\ingcii ulicr .Vmiudsauren. Pdlypc^ptidc uiid Pmlrinr nSOn-IOnO'i. r.crliii. 
1!I(m;. 

f'.\.li(|Unt sliniild riiiicsiMii ajipri ixiiiuit I'l v (t.2 t;ram nl' a lil■^l rla^s, miIiiI lici-l 
ex i met. 

'• Zts. pliysinl. Chciii., liiOl, 4! ;223. 



40 MEAT EXTRACTS. 

Definite amounts of kreatin and kreatinin were added to samples 
of meat extracts and practically the entire amounts added were 
recovered by this methotl. The color of the various extracts inter- 
fered slightly with the reaction and attempts were made to remove 
the color by i)recipitatino; with basic acetate of lead and pliospho- 
tungstic acid ami by filtering through animal charcoal. In all such 
cases, however, low results were ol)tained on testing the tiltrate for 
kreatinin. Consecjuently, in this work the kreatinin method was 
applied directly to the coagulable protcid filtrate and no allowance 
was made for the error due to the color. Since the method calls for 
a dilution to 5U0 cc and but 10 to 15 cc are used for the determination, 
this error is negligible. Grindley and Woods" have determined 
separately the kreatin and kreatinin content of several extracts of 
meat and found both present in varying amounts. It is necessary, 
therefore, to determine these two liodies separately when a careful 
study of the nitrogenous bodies of meat extract is made. Some later 
experiments in the Bureau of Chemistry have shown that three and 
one-half hours heating in a boiling water bath is necessary fur the 
complete conversion of kreatin into kreatinin. Benedict and Myers* 
have described a rapid method for the estimation of kreatin and 
kreatinin by conversion into kreatinin in an autoclave. This 
method reduces the time of dehydration of the kreatin to fifteen 
minutes. 

APPLICATION OF KREATININ TEST TO TANNIN-SALT FILTRATE. 

In view of the fact that a portion of the kreatin in a sample of 
meat extract is precipitated by the tannin-salt reagent ' the total 
kreatin and kreatinin in the filtrate from the tannin-salt precipi- 
tate is determined, as well as the total kreatinin in the extract, before 
adding the reagent. A more correct figure is accordingly obtained 
for the total meat bases by adding to the total meat bases figures the 
amount of total kreatinin precipitated by the tannin-salt reagent. 
In applying the Folin method to the filtrate of the tannin-salt pre- 
cipitate considerable difliculty was encountered. The tannin was 
removed by means of baryta and the barium with sulphmic acid. 
After neutralizing, the total kreatinin was determined in the usual 
manner. In the estimation of the peptones, correction must like- 
wi.se be made for the amount of kreatin and kreatinin precipitatetl 
by the tannin-salt reagent. 

Xanthin Bases. 

In addition to kreatin and kreatinin, a true meat extract or meat 
juice should contain small amounts of xanthin bases, including 
xanthin, hypo-xanthin, guanin, and adenin. These bodies are de- 



« .1. Bi<il. ('hem. , 1907, ;.' : 309. c J. Amer. Chom. Soc, 1906, SS : 1485. 

^Amer. J. Physii.l., 1907, ;cV::»7. 



METHODS OF ANAL\>1[S. 41 

rivod from the nuclei of the cells, ami, conseijuently, in an extract 
that is prepared from fresh, unaltered hcef a certain amount of these 
bodies should be obtained together with the salts and other extractive 
matter. The determination of the xanthin bases is, therefore, of 
value in determining the origin of an alleged extract of meat. 

The xanthin base figures in the tables show a variety of residts, 
which is explained by the fact that in the preparation of the extract 
inider certain conditions of heat and pressure some of these bodies 
are <lestroyed. The following modification of Schittenhelm's method 
was employed for their determination: 

I'.se an aiiioiint of tho standard scilution e(]uivulcm In 5 granir^ of the original oxirart. 
Place in a large evaporating diph and add 500 ci- of 1 per cent sulphuric aciil- Eva])- 
oralc to 100 cc within 4 to 5 hours. CocjI and ueulralizc willi .sodium hy(hoxid. 
,\dd 10 re of 15 per cent sodium hisulphate, and 15 vv of 20 per cent coppor sulphaiis 
allow tliis to stand over night, filter, and wash. The precipitate suspended in water 
is treated with sodium sulphid and warmed on the steam bath. .Vdd aeeiir acid to 
acidify and filter hot. To the filtrate add 10 cc of 10 per cent hydrochloric acid and 
evaporate to a volume of about 10 cc. Filter, make ainmiuiiacal. and add amuio- 
niaeal silver nitrate of 3 per cent strength, .\fter standing several hours tlic .Mplution 
is filtered and washed with distilled water uulil no l.uiger alkaline. Tin nilroircn 
in the precipitate is that of thi- xanthin bases. 

.\mM(INI.\. 

Ammonia in meat extracts is determined by the method" (d' the 
As.sociation of Olilcial Agricultural Chemists, which consists hi distill- 
ing the sample in the presence of magnesium o.xid. In several of the 
samples examined high ammonia results were o})tained which might 
indicate some degree of putrefaction. It is ((uestionalile, however, 
whether the ammonia results obtained l)y the magnesium oxid 
method are not too high. 

Many investigators have stated that ammonia salts are |)reseiit in 
nieat extracts. Probably the ammonia combines with acids of the 
fatty series to form these salts, which are solulile in alcohol and vola- 
tile with alcohol vapor. The ammonia is estimated by dissolving 10 
grams of the meat extract in water, adding barium carbonate and 
distilling. It has been suggested that ammonium salts, especially 
ammonium sulphate, are added to meat preparations to increase the 
nitrogen content, and in some of the extracts examined a relatively 
high sulphur content was noted. 

SUCCINIC .VCID. 

Weidel ^' first called attention to the presence of succinic acid in meat 
extracts. Salkowski, '' Kutscher and Steudel,'' ami others claimed 



1 U. S. Dcpt. Agi-., Bureau of Chemistry, P.ul. 107. p. 0. 
b Liebig's Annalen, 1871, 1.5S : 3.53. 
I'Zts. klin. Med., 1890, Supplement to vol. 17. p. 77. 
<lZts. physiol. Chem., 1903. .«: 101. 



42 MEAT EXTRACTS. 

that succinic acid was a putrefaction product and its presence in 
meat extract showed that fresh meat had not beeti used in manufac- 
turing the extract. Siegfried" held that tlie source of the succinic 
aciil is a definite substance of acid character and he called this sub- 
stance " Phosphorfieisch Saure" or "Muskelnucleon." Later work, 
however, indicates that succinic acid is a cleavage product of fresh 
meat formed by the action, at high temperature, of tlextrose or other 
reducing substance on amido acids, especially aspartic acid. Conse- 
cjuently, the presence of succinic acid in a meat extract does not 
mean tliat spoiled meat was used in its manufacture. In 1904 two 
or tliree brands of American meat extract were tested for the pres- 
■ence of succinic acid by means of ether extraction and the pine sliver 
test tmd this body w'as shown to be present. 

Tile questi<Mi of the presence of succinic acid in meat extracts is 
thoroughly discussed in a recent publication of the German Board of 
Health.'' " 

ETHER EXTRACT. 

The ether extract shoukl not be above 0.6 per cent in a sample of 
meat extract, as the fat is liable to become rancid and injure the 
flavor of the product. Moreover, a high fat content shows lack of 
care in preparing the extract. 

The provisional methotl employed for determining the ether ex- 
tract <^ is conducted as follows: 

Dry the sample over night in the presence of dry sand in a lead dish 
at the temperature of boiling water. Then thoroughly grind and 
extract the dried sample with anhydrous ether, in a continuous ex- 
traction apparatus for sixteen hours. Satisfactory duplicate results 
are obtainable by this method, but it is the opinion of the authors 
that the sample should be digested with pepsin and acid before ex- 
tracting with ether, in order to break iip the proteiil matter aiid thus 
expose the fat to the action of the ether more completely. 

GLYCEROL. 

That glycerol has oeen addeil to fluid meat extracts and other 
similar preparations is well known, and it was found in several of the 
samples i-eported in this bulletin. The purpose in adding it seems 
to be to give the product additional smootluiess and body. More- 
over, glycerol is of considerable value as a preservative. Glycerol 
is burned in the body and thus becomes a source of energj', but it 
does not act as a proteid sparer. 

Various methods were tried for the determination of glycerol in 
meat extracts and related products, including the method of the 

" Zls. physiul. Clu-m., 1903, .J,9 : 12G. 

'' Arb. kuLsi'd. GesundlKntsamtc, 1900. vol. 24. 

cU. S. Dept. Agr., Bureau of Chemistry, Bui. 107, p. 114. 



METHODS (IF ANALYSIS. 43 

Association of Official Agricultural Cheinists" for the (Ictcniiina- 
tion of glycerol in wines, and Lane's method,'' as well as numerous 
extraction methods. Among the solvents used were benzol, amyl- 
acetate, gasoline, carbon tetraclilorid, carlion bisidpliid, and acetone. 
All of these solvents extract varying amounts of meat bases, or 
extractives, and give different results on the glycerol present. The 
following reagents were used to precipitate the dissolved meat bases: 
Lead acetate, silver nitrate, and phosphotungstic acid. The best 
results were obtained by extracting with acetone, the meat bases 
being precipitated first witii silver nitrate, followed by phospiio- 
tungstic acid. The glycerol in the filtrate was estimated by the 
Ilehner '' method. 

Shukoff and Shestakoff '' describe an acetone extraction metliod. 
but weigh the glycerol, and it is impossible to estimate this body in 
the case of meat extracts by weighing on account of the salts and 
extractives dissolved by the acetone and weighed as glycerol. 

A method using anhydrous copper sulphate and extiacting witli 
acetone is now under investigation. 

NITRATES. 

A qualitative test for nitrates was maile in 2s samples of meat 
extracts, meat peptones, fluid meat juices, and fluid extracts. The 
samples were collected in July, 1907, and in general represent the 
same brands as were used in the other studies. 

The diphenylamin ■= test was used. The reagent was made by 
dissolving f jiart of diiihenylamin in 100 parts of concentrated sul- 
pliuric acid. Tiie test was applied as follows: 

Transfer l.,5 grams of the semisolid, or 1 cc of the licfuid extracts, 
to a 250 cc beaker and boil with animal charcoal for two or three 
minutes. Filter tiie .solution hot and test one drop of the filtrate 
on a porcelain plate with three tlrops of the diphenylamin reagent. 
A blue color indicates nitrates, and the depth of color shows in a 
general way the amount of nitrates present. 

Negative tests for nitrates were obtained in the case of 14 of the 
28 samples examined. The results on the 14 samples giving posi- 

" U. S. Dept. Agr.. Bureau of (.'hemistry. Bui. 107, p. 8:3. 

i Unpublished. The method reads a.s follcjws: 

Precipitate a known weight or volume with basic lead acetate, make up to a known 
vokiine with alcohol, filter, take an aliquot part, add a little anhydrous lime, distil 
nearly to dryness in a steam laath (keep the flask inimer.sed), add an excess of anh\- 
drous CaO, mix. moisten with alcohol to facilitate mixing if neces.sary, distil again 
on steam bath to combine water with t'aO, and extract with two-thirds alcohol and 
one-third chloroform, as usual. 

cj, Soc. Chem. Ind., 1889, S-A. 

dZts. angew. Chem., 1905, lS:2'^>i. 

fAriti. Hyg., 1SS4, J -.373. 



44 



MEAT EXTRACTS. 



tivc reactions showtnl in 6 cases a slight trace and in 8 cases a very 
strong reaction, indicating that the "hquor" from the parlxiihng of 
corned beef was used in tlieir preparation. (See jx 13.) 

UNDETERMINED MATTER. 

Under this head are included nonnitrogenous organic matter as 
well as glycerol and carbohydrates. Glycerol has been considered 
imder a separate caption. The amount of undetermined matter 
present depends on the mode of preparation of the extract; not 
niore than 10 per cent should be present in a meat extract. Inosite 
and various aniido acids, from which the nitrogen has been sjilit oft", 
also constitute a portion of the undetermined matter. 

Several of the samples which gave a high per cent of undetermined 
matter were tested f(n' starch, reducing sugar, and glycerol. The 
following (|ualitative results were obtained: 

Qualitative tests for starch, reducing sugar, and glycerol. 





Sample. 


Starch. 


Sugar. 


Glycerol. 


l.'jMlO 


Present 

None 

Present 

Present 

None 

None 


None 

None 

Trace 

Present... 

None 

None 




loOfili 


Present. 


1.1977 




Hi041 


None. 


1(.04S 




1(1049 


1 Present. 









The al})nmose and peptone products which are high in nndeter-- 
mincd matter, according to the tables, contain carbohydrates (starch 
and sugars). In the case of several of the ftuid meat extracts, or 
juices, and in one or two solid extracts, glycend is present. 

HISTORICAL NOTE ON NUTRITIVE VALUES. 



GELATIN. 

It has long been known that gelatin is present in various anioiuits 
in meat extracts. The collagen of the muscle on hydration yields 
gelatin, and if the hydration be carried far enough soluble gelatin, 
gelatoses, and gelatin peptones are found. Gelatin, while rich in 
nitrogen, is not capable of keeping the body in nitrogenous equilib- 
rium, since the nitrogen is not present in a form available to the body 
as in all true proteids. This has latel}' been explained by Kauff- 
mann " on the ground that the gelatin molecule is lacking in the 
tyrosin, cystin, and tryptophane groups and that h\ feetling these 
amido bodies with gelatin animals are kept in nitrogenous equilibrium. 

Kauffmaun states that one-fifth of the proteid of a ration can be 
replaced by gelatin, but when used in large proportions the body is 



'Pfliiscr's .\rch., 190.5, 109 :440. 



NI'TRTTTVE VALI'ES. 45 

not kept ill e(|iiilil>riuin. This was ilcnioiistratetl liy an ex])(>riiiicnt 
coiKhictod by the author on himself, and also on doirs. Manrini" 
has fed lar<j;e amounts of i^clatin and little proteid and claims that 
gelatin has a proteid s])arin(; action. Murlin'' has re]ilacod two- 
thirds of the proteid nitrotren by gelatin in the case of both dogs and 
men reduced to a starvation level and linds the equilibrium is not 
changed by this substitution. Gelatin and its cleavage i)roihicts have 
been studied by C^iittenden and Solley '' and Levene '' among others. 

A valuable contribution to the literature on the sid)ject of the nutri- 
tive value of gelatin by Murlin' has recently appeared. The re\iew 
of the literature here given is in part taken from this article. The 
experiments performed by this author were made on dogs and the 
fasting requirement of nitrogen was used as a working basis. Murlin 
states that the power of the organism to utilize gelatin as a pi'oteid 
substitute depends to some extent on the proteid condition of the 
body at the beginning of the experiment, as well as u|)on the loss of 
proteiil during its progress. 

In the experiments with dogs as high as 58 per cent of gelatin nitro- 
gen was substituted for proteid nitrogen, the amount varying with the 
diet. In the case of man, if two-thirds of the pot(>ntial energy were 
in the form of carbohydrates it was found to 'oe possible to supply (J.'] 
per cent of the total nitrogen in the form of gelatin nitrogen for a 
period of two days and maintain a daily retention of nitrogen of 0.71 
gram. 

Exact knowledge of the nutritive value of gelatin had its beginning 
in the researches of Carl Voit,'' published in 1872. As early as 1S60 
Voit and Bischoff'' had established experimentally the truth first 
perceived by Bonders,'' that gelatin reduces the proteid requirements 
of the l)ody: but they were of tlie opinion at this time that it could 
perform all the work of proteids and replace tluun entirely in tiie diet. 
After Voit' had shown that a part only of the nitrogenous excreta 
is ilerived from the jtroteids of the body tissue, a portion coming from 
the '"circulating" proteids, he again investigated the extent to which 
gelatin coidd be substituted for ])roteid, and reached the following 
conclusions: 

Gelatin exercises its sparine |i(iwer on tlie jimleid.s IkjIIi with l:iri,'c anil witli snuill 
quantities of prciteid (meat) fed at the same time, and with small quantities in much 



"Arch. d. Farmacol. speriin., IflOfi, .;: 309, ,337. 

bProe. Soe. Exper. Biol, and Med., 1904. ;.^:3S. 

cj. Physiol., 1891, 7i:23. 

dZts. physiol. Chem., 1904, .;j:8. 

fAmer. J. Physiol.. 1907, /,'/:2S7. 

/Zts. Biol., 1872, 5:297. 

? Die Gesetze der Ernahriinff des Fleischfressers. l.eipzit;. l.%0. 

''Die Nahningsstofte, Crefeld. 18.J3. 

'Zts. Biol., 1869, 5:329. 



4*1 MEAT EXTRACTS. 

higher degree than either fat or carbohydrates. It can be shown that large quantities 
ol gehvtin spare more pro teid from combustion than do small quantities; that, however, 
proteid is lost from the body even if with largo quantities of gelatin the greatest possible 
amount of fat be given. A direct laying-on of gelatin, either in the glutin-yielding 
tissues or in the proteid-forming tissues, is not possible, and it must therefore be 
assumed that when gelatin is formed in the body it is at the expense of proteid. Gela- 
tin, for this reason, is capable of replacing proteids of the food only in jjart." 

Voit made no special attempt to set the limits witliin which proteid 
may be so replaced, but gives for a large dog these figures: 168 grams 
of dry gelatin spared 84 grams of dry flesh.* 

The next investigation bearing on the comparative value of gelatin 
and proteid was that of Oerum,'' who placed a dog on a daily diet of 
meat, starch, butter, and meat extracts; he then replaced all of the 
meat with enough gelatin to maintain the same nitrogen supply. He 
records a considerable increase in the nitrogen of the urine in the 
latter case. 

Pollitzer,"' in the course of some experiments undertaken to prove 
that the products of proteid digestion are to be classed with the pro- 
teitls themselves, and not with the proteid-sparing foods merely, 
compared the eflfects of gelatin on the nitrogen output with those of 
horseflesh and its products of gastric digestion. He concludes that 
pejitone and liemialbumose (prepared by Kiihne's methods) have a 
nutritive value wliich is in "sharp contrast with the considerable loss 
of nitrogen which takes place after feeding an equivalent amount of 
gelatin." 

Ganz'' fed Paal's glutin-peptone and was able to cover more than 
half of the total nitrogen requirements therewith. Gerlach'' also pre- 
pared a "glutin-peptone," and found that it is a good "sparing agent," 
but is not of itself al)le to replace prc)teid. 

Munk s in a brief series of experiments attempted to find the "upper 
limit for the substitution of food proteiil with gelatin," and reached 
the conclusion that at lea-st half as much proteid must be fed as is 
destroyed by the animal in fasting, if nitrogen equilibrium is to be 
maintainetl. 

Kirchmann,'' m a very painstaking research with proteid-free 
gelatin, determined that the proteid destruction may be reduced 
under the influence of gelatin alone as much as 35 per cent, and that 
this maxinium effect is obtained when 62 per cent of the body's 
energy requirement is supplied by the gelatin. 

"Zts. Biol.. :S72, .s^297. 
6 Ibid. 

i-' Nordiskt medicinskt Arkiv, 1879, vol. 11, reviewed by Hanimarsten in Maly's 
Jahresbericht fiir Thierchemie. 1879, .9: 308. 
'I' Archiv gesam. Physiol., 1885, 37 : 301. 
f Quoted by lUrchmann. Zts. Biol., 1900, -;o:54. 
./■ Die Peptone. Haml)urg and Leipzig, 1S91. 
g Archiv gesam. Physiol., 1894, oS : 309. 
>' Loc. cit. 



NUTBITIVE VALUES. 4 I 

KruminacluT," farrviiit; the wtirk beijun by Kirchmanii si ill 
further, found tliat when the entire energy requirement of the dog 
was covered by gelatin the total sparing was only 37.5 per cent of 
the fasting nitrogen. Applied to a man who.se energy recjuirenient 
is 2, .500 calories daily Krunnnacher calculates that if .5 per cent of 
his recjuirements were supplied in gelatin (i. e. about 33 grams of dried 
and purified gelatin), the proteid destruction in his body would be 
reduced from 70 grams to about 56 grams, or, in other words, the 33 
grams of gelatin would replace 14 grams of proteid. 

Gregor* used gelatin in feeding infants in certain cases where 
excess of proteid was contraindicated, and concluded that with a diet 
containing 4.8 grams of nitrogen per day (of which ''nearly all" was 
gelatin X), not more than iialf as much nitrogen was lost from the Ixidy 
as in starvation. 

Braf prepared a gelatose, which he identifies by Chittenden's'' 
method as a deuterogelatose, and fed it to convalescent patients as a 
substitute for a portion of the proteid in their diets. 

Mancini"^ studied the nitrogen balance of five convalescents from 
tj'phoid fever, while giving '"large cpiantities" of gelatin. He 
observes a considerable retention of nitrogen, but doubts whether 
proteid nitrogen can be replaced by gelatin nitrogen. 

Kauffmann^ studied the replacing power of gelatin in a diet con- 
taining "only as much proteid (mainly casein) as is necessary with a 
sufKcient supply of energy for maintenance of the body's condition." 
He concludes from his experiments on dogs that not more than one- 
fifth of the proteid in such a diet can be replacetl by (pure) gelatin 
if nitrogen equilibrium is to be maintained. With one-fourth of the 
prcjteid nitrogen so replaced a small minus balance occurs. Kauff- 
mann's paper is concerned chiefly with the attempt to bring gelatin 
up to th(> full nutritive value of proteiil by adding to it the amido- 
aciils which it lacks, but which casein contains. 

Rona and Miiller," in attempting to confirm Kaulfmann's residts 
with gelatin, tyrosin, and tryptophan, found first "the smallest 
quantity of proteid nitrogen with which the animal could well get 
along," and then replaced one-fifth of this proteid (casein) with 
gelatin nitrogen. Their observation as regards the amoimt which 
would be replaced was quite in accord with Kaufl'mami's, for when 
gelatin was substituted for two-fifths of the casein there was a dis- 
tinct minus balance. 

«Zt.s. Biol., 1901, .^.':242. 

(i Centi-alblatt fiir inucre Medicin, 1901. .'? : 65. 

c Deutsche medicitiLsche Wochenschrift. 1902. p. 21. 

rfj. Physiol., 1891, 12:2i. 

<■ Reale .^ccademie dei Fisiocritiei di Sieni, 190-5, I7;(j()7. 

/.Vrchi\-gcsam. Physiol., 1905, 70.9:440. 

sZts. physiol. Chem., 1907, 50:263. 



48 MEAT EXTRACTS. 

The conclusions reached by the various investigators may he sum- 
marized briefly as follows: Gelatin can replace proteid only in part 
(Voit, Oerum, Pollitzer); it has, however, a high proteid-sparing 
effect, whether fed alone (Kirchmann, Knnnmacher), or with other 
foods (Yoit, Oerum, I. Munk, Kaufl'mami, Rona and Midler) in infant 
feeding (Gregor), or in convalescence (Brat, Mancini); this proteid- 
sparing effect is exerted also by gelatin-peptones (Ganz, Gerlach) 
and gelatoses (Brat). 

MEAT EXTRACTS .VND JUICES. 

The various protein bodies and amido acids are so closely asso- 
ciated that it is impossible to produce amido acids without produc- 
ing albuminoses and peptones. Consequently, every commercial 
meat extract must consist partly of albuminoses, peptones, etc. The 
best extracts on the market to-day contain about 50 per cent of the 
total nitrogen m the form of meat base nitrogen. Wlien a meat 
preparation contains only a small amount of its nitrogen in the form 
of meat base nitrogen, the term "extract" seems to be no longer 
applicable. And it is evident that the product represents much less 
meat than an extract with .'SO per cent of its nitrogen in the form of 
meat base nitrogen, pro\dded the total nitrogen in both cases is 
apjjroximately ec[ual. Moreover, it is necessaiy to distinguish 
between a meat extract containing large amounts of stimulating amido 
acids and relatively small percentages of albumoses, peptones, and 
msoluble proteid matter, and an extract (or, more properly, a meat 
product) wliich consists largely of albumoses, peptones, and insoluble 
matter and relatively small amounts of amido acids. The food value 
of this last group of products is undoubtedly greater than that of the 
former group, but the}' should not be classed as extracts because 
of their different nature. The value of the amido bodies as food is 
uncertain, but at least they furnish energy to the body. It appears, 
therefore, that the value of meat extracts lies principally in their stim- 
ulating (jualities, the active principles of tea and coffee being on a 
similar liasis. 

The question of the nutritive value and relative worth of the vari- 
ous nitrogenous, constituents of meat preparations is a much-dis- 
cussed but unsettled problem. Beef juice prepared fi'om fresh beef 
by )>ressure and heating and used unchanged is an ideal product, 
containing the extractives as well as a large amount of nutritive 
material. As a commercial product, however, it is impracticable. 
The higher forms of nitrogen, insoluble proteids, alkali and acid albu- 
mins, and coagulable proteids, as well as the vmchanged proteids, are 
the most desirable forms for the healthy individual. The invalid 
may require partly digested proteids, such as proteoses and peptones. 
A large amount of nitrogen in this form should be avoided, as manj' 



rf 



KUTKITIVE VALUES. ■ 49 

investigations have shown that (liarrlupa and other disorders follow 
the feeding of peptones. The stinuilating properties of the amido 
acids are most valuable in that they create an appetite and pi'epare 
the sj-stem for food. 

The scojje of this report will not permit of the exhaustive treat- 
ment of tills subject, but brief mention is made of the following con- 
tributions as indicative of the tendency of the results obtained: 

Biirgi" states that meat extracts are not foods, and that all mate- 
rial taken in this form is quickly eliminated. Only 4. .57 per cent of 
the nitiogen, 14.S.5 per cent of the carbon, and 17.55 per cent of the 
energy content is retained. According to Rubner' meat extracts, 
after they have served their purjiose of stimulating digestion, are 
eliminateil from the body as rajiidly as possible. W. H. Thompson'' 
has fed arginin to dogs and found \'i\m\ 37.(5 to 77 per cent in the 
urine; on injecting ai'ginin SL' ]K'r cent appeared in the urine. A 
part of the arginin nitrogen ajijieared in the vu'ine as ammonia. Yoit 
claims that the value of meat extracts lies in their flavor, which pro- 
motes the flow of the digestive juices. As the constituents of meat 
extracts are largely in a form ready for elimination, Rubner'^ holds 
that they have little food value. 

Pfeift'er, Einecke, and Schneider' have fed asparagin tii cows and 
report a favorable efl'ect on the milk antl its constituents, and W. 
Voltz*' claims asparagin can replace proteid without lowering the 
quality of the milk and that it acts as a proteid sparer in herbivura. 
In oumivora its proteid sparing power is small and it seems to have 
no such power in carnivora Imt rather increases proteid cleavag(\ 
In feeding experiments with mice on a zein ration Willcock and Hop- 
kins '' found that on adding tryptophane to the ration the lives of the 
mice were lengthened. Ilenriques and Hansen ' have maintainetl 
nitrogenous equilibrium on feeding hetero-albumose. 

Rubiier-' discus.ses the alcohol-soluble and alcohol-insolultle por- 
tions of fluid beef. The nutritive value of fluid beef is considered at 
length and the author concludes that if enough of such product for an 
entire ration were taken the cost would be enormous. The claim tjuit 
two teaspoonfids of fluid meat have a nutritive value equivalent to 
one and one-fourth pounds of cooked meat is deemed correct. Two 

".\rch. Hysione. 1004, .07:1. 

''Ibkl. p. 19. 

cj. Physiol.. 1905, .;;j:ll)(;. 

dStoffweehsel, 1882, p. 449. 

fZts. Biol., 188,3, 7.9:,343. 

/Mitt, landw. Inst, konigl. Univ. Broslau. UIO.'i, .;:179. 

ffFiihlingsIandw. Ztg., 190.5, .>; (2i:41; (,:i): 9(i. 

''J. Physiol., 1906, 35: 88. 

iZts. physiol. Chem.. 1900, .;,v : ;S8;5, 

iZts, Biol., 1879. 7.5:4.85. 

4:5689— Bill 1.11 4—08 4 



50 MEAT EXTKACTS. • 

teaspoonfiils of lluiil meat weigh about 5'2 grainy and are ec^uivalent 
to 65 grams of pure meat free from fat and bones. Barker"^ recently 
published a thorough review of the question and has taken up several, 
new points. In normal man the aniido bodies do not appear in the 
urine to any extent; therefore, they must be of value, and the author 
believes they are synthesized into protein by the cells of the small 
intestine. W. Voltz'' claims that amido bodies of different chemical 
constitution produce varying effects on the nitrogen and caloric bal- 
ances of the body. The tightly bound NH„ groups, holding an inter- 
mediate position in the molecule, such as are found in glycocoll, tend 
to increase the nitrogen retention less than the carboxyl XH., groups, 
wliich are more easily separated from the molecule. The amids in an 
ordinary diet give more favorable results than when fed alone. On 
feeding various amids to dogs the author obtained favorable results. 

An unsigned article in the Pharmaceutische Zeitung'^ discusses the 
manufacture of meat extracts, and says that when meat (fat and bone 
free) is extracted with water by heating, the extract does not taste 
like the commercial meat extract, and is wMtish, but after continued 
heating over an open fire and the addition of 30 per cent of salt, the 
commercial product, a brown aromatic extract with a characteristic 
taste, is obtained. In preparing meat juice, 1 pound of meat cut up 
and pressed yields 60 to 100 grams of a red-colored juice. Evaporate 
this at 60° C. in a vacuum to one-tliird its bulk and a slightly red 
solution with a taste of meat, but no salty taste, is obtained — a 
product differing from the commercial article. It contains 30 per 
cent of coagidable nitrogen. If a little of the solid commercial meat 
extract is added, we have the commercial meat juice. This article is 
answered by L. Geret,"* who tells of the virtues of Liebig's extract. 
H. Otto*^ claims that meat extracts contain no nutriment, and that the 
fine odor and aroma of meat bouillon is destroyed in the commercial 
product. 

Tlie nutritive value of beef preparations is also discussed by Chit- 
tenden.^ Liebig's and Armour's extracts were analyzed and found to 
consist largely of soluble extractives and inorganic salts of muscle 
tissue. The nitrogen is liigh but not to any extent available for the 
body's use, and according to Kemmerlich an animal fed on extract of 
beef mil succumb cpiicker than an animal not fed at all. Extracts are 
useful on account of their stimulating and restorative value. The 
content of potash salts causes a cpiickened and stronger heart beat. 
An extract of beef is more like an alcoholic stimulant than a food. 
Meat juices such as Wyeth's and Valentine's, according to Chitten- 
den, have little food value, resembling dilute meat extracts. 

« British Med. .1., Oct. 27, 1907. 'I \hU\.. p. 31C. 

ftArch. ges. Physiol., 1906, i;.^;413. <■ Il.id., p. 350. 

:197. /M«l. News, 1891, 55:716. 



XT'TRITIVK VALUES. 51 

Tlir cxplaiiatiuii of tlu^ oxidation of tlie various aiuiilo aciils in (lie 
Ijody is now generally referred tu the relative jxisition and nund)er 
of carl)on atoms in the side chains. Sehotten," Pohl,'' and Knoo])'' 
have investigated this point quite thoroughly. The extent to 
•which the administration of various aniido acids will maintain tiie 
nitrogen ec[iiilihrium was fh-st investigated by Loewi/ who showed 
that the end jiroducts of digestion which no longer gave the biuret 
reaction are still able to replace tiie albumins destroyed during 
metabolism. 

Abderhalden and Bergell '' liave shown tliat amido acids when 
given in moderate amounts (glycocoll up to o grams; alanin, :) grams; 
leucin, S grams; phenylalanin, 3 grams) are completely destroyed in 
the body. Stolte' injected various amido preparations into a rabbit 
and found an increased urea output in all cases. According to Alann » 
the first change which the amido acids undergo in the body is prob- 
ably that of oxidation. oxy-acid.s being formed as occurs in plants 
and in alcajitan-urea when tyrosin and phenylalanin are changed 
into homogentisinic acid. It is an open cjuestion whether the carl)on 
chain, after the splitting off of the nitrogen wiiich forms urea, breaks 
up still further or whether it is utihzed in the building up of otlier 
nonnitrogenous substances, such as carl>ohydrates and fats. Wohl- 
gemuth'' by feeding rabbits with the inactive or racemised mono- 
amido acids (such as tyrosin, leucin, aspartic acid, and glutaminic 
acid) found that the ina<'tive acids become dissociated during meta- 
l)olism in such a way that the component occurring normally in the 
body is oxidized as far as it can be assimilated while the abnormal 
component is excreted partly or completely in tlie urine. 

The occurrence of monoamido acids in the urine during normal 
and pathological conditions has been studietl by Abderhalden,' Ab- 
derhalden and Bergell,-' Ignatowski,'' Abderhalden anil Barker,' and 
Erben.'" Loewi and Xeuberg" have studied the diamins of the urine. 
vSince the tliscovery of the enzym erepsin in the intestine the idea is 
rather generally accepted that the ])roteid molecule is broken down 
in part, at least to the ammonia stage, and the ammonia and other 
groups are synthesized into the characteristic bod}' protein through 
the agency of the epithelial cells of the villi of the small intestine antl 
transported by tiie lym])ocytes through the blood stream to the 
tissues. 



" Zt.'i. physiol. Chem., 188;?, fl : 60. * Bcr. d. chem. Ges.. 190.5. -IS : 2064. 

i- Arc-li. expor. Patli. Pharm., 1S96, S7: 413. i Zt.-f. physiol. Chem., I!t03. .ig : 5.37. 

c Hofmeister's Beitrage, 1904, 6 : 150. J Ihid.. 1903. J9 : 9, 464. 

'' Arch, r-xper. Path. Pharm., 1902, 4S: 30;i t Iliid.. 1904. 42 : 371. 

( Zts. physiol. Chem., 1903. 39 : 9. I Il)i(l.. 1904, 42 : 524. 

/ Hc.t'meister's BeitrSgc. 1903, .', : 15. m Ihid., 1904, 4J : 320. 

a Ch./migtry of the Proteids. 1906. » Iliid., 1904, 43 : 355. 



52 MEAT EXTRACTS. 

In a recent article on the physiological action of muscle extracts, 
J. G. Slade" states that muscle extracts were formerly supposed to 
represent the whole nutritive value of the meat, but recently all 
nutritive power has been denied them, and indeed, except for such 
traces of albumin, fat, or peptone as they may contain, it is difficult 
to see whence such food value would come. This author concludes 
that muscle extract has no stimulating effect upon man's central 
nervous system nor upon the power of performing physical work. If 
taken as a strong solution or in large amounts it is lia})le to cause piu'- 
gation. In moderate doses it stimulates the action of the heart. 
This is not due to kreatin, xanthin, or urates. The movement of the 
plain muscles throughout the body is increased, which is probably 
due to ornithin and novain. Muscle extract in 0.5 per cent solution 
ircreases the power of the voluntary muscle, in 0.1 per cent solution 
it has no effect U])on the efficiency of the muscle, and in 0.2 per cent 
solution this is decreased. Xanthin has an action corresponding to 
the first effect; that is, in saturated solution it increases the efficiency. 
Kreatin has no action on voluntary muscle. The effect of fatiguing 
a muscle before preparing an extract from it is to increase its extract- 
ives and increase the activity of the extract. If injected into ani- 
mals it causes great languor, prostration, and all the symptoms char- 
acteristic of fatigue. Muscle extract administered as "beef tea" 
acts as a moderate diuretic to men and other animals. The iliuresis 
is associated with vasodilatation of the kidney. 

Dr. O. Dornlikitii * discusses the preparation and comjxisition of 
various meat extracts, powders, and other preparations. Xutrose 
and milk casein products are considered. 

Dr. J. Price' gives a recipe for prejiaring home-nuide meat extract 
after the general plan of Liebig's original recipe. lie considers that 
meat extract or juice prepared as he describes it is highly nutritious. 

A. Brestowski"'' claims tiiat meat extracts possess no food value, 
l)ut on account of the meat bases, potassium phosphates, and their 
flavor they have value in increasing nuiscle activity and the secretion 
of the gastric juice. The food and therapeutic value of peptones is 
discussed. 

Pawlow ^ says that muscle extract is a stimvdant to an exhausted sys- 
tem and assists digestion. Pawlow has shown that muscle extracts 
are stomach stimulants and cause a flow of gastric juice. He fnund 
also that the individual extractives, such as kreatin and kreatinin, were 

a J. Physiol.. 1907. 3.5 (3): 163. 
bAerxtlicho Monatschrift, 1898, L>:49. 
c Philadelphia Polyclinic, 1894, p. 93. 
d Medicin.-Chir. Centrbl., 1893, :^S:Cb3. 

"■The Work of the Digestive Glands, 1897, translated from the Russian liy \V. H. 
Thompson, London, 1902. 



NUTRITIVE VALUES. 53 

ineffectual, and coiicludeil lliat tlie specific substance causiny; the 
stimulation was not known. 

Brunton" makes the followinj,' statement in regard to the efl'ect of 
beef tea or beef essence: 

We find (inly tun fn-(|Ui'iitly thai Iwith (Idctcjrs and patients tliink that the strength is 
sure to l)e kept np if a sufficient ([nanlily of beef tea can only be got down; l)Ut this 
oljservation, I think, raises the question whether lieef tea may not very freqiunitly lie 
actually injurious, and whether the i)roducts of muscular waste which constitute the 
chief portion of \ieef tea or lieef essence may not under certain circumstances l^e act u- 
ally poisonous. Fi>r although there can be no douljt that beef tea is in many cases a 
most useful stimulant, one which we find it very hard, indeed, to do without, and 
which could hardly be replaced by any other, yet sometimes the administration of 
beef tea, like that of alcoholic stimulants, may be overdt)ne, and the patient weak- 
ened instead of strengthened. 

Mays'' asserts tliat beef tea is entitled to be called a nutrient 
because its action is the same as tiiatof milk, or a 2 per cent solution 
of ox blood. In a later jiaper'' he a.scribes this nutritive vahie to the 
kreatin and kreatinin ]>resent. 

Dr. Tjchinan'' discusses the action and the toxicity of meat extracts 
and concludes that Liebig's extract is not a heart juiiscin, but is rather 
an aid to the heart. Both in hciiith and in sicknesss as much of the 
extract can be used by the body as the stomach can stand. Home- 
made meat extracts contain more potash than ecpiivalent amounts of 
Liebig's extract. 

Dr. Carl Voit <■ gives a very able discu.ssion of meat prejiarations 
and considers them of great value as a condiment, but not as a food. 

Dr. N. G. Vis^' conducted a set of experiments on men, using a 
mixed diet, including beefsteak in the first period. For the beefsteak 
he substituted in the second period an equivalent amount of nitrogen 
in the form of sanatogen, a .sodium-casein-glycerol-phosphoric-acid 
compound. There was an increased excretion of nitrogen in both 
urine and feces in the second period. 

Frentzel and Toriyama^ in opi)osition to Rubner find that of the 
proteid-free extractive material of meat about two-thirds takes part 
in metabolism in that it furnishes energy to the body. 

Dr. Emil Biirgi'' has studied the question of the heat and energy 
value of meat and meat extractives in the ca.se of dogs. ITis results 
show that meat itself is a much more valuable soiave of energy than 
are the meat extractives. 



3 The Practitioner, 1880, i.5:325. 

bThe Lancet, 1886, ^:510. 

clbid., 1887, 7:257. 

d Aerztliches Intelligenz, 1885, .)V::5]8. 

« Miinchener medic. Woclienschr.. bs!i7, -;.(:221. 

/Ibid., 1898, 4-5:257. 

ffAreh. Anat. Physiol., Physiol. Alit., illOl, \>. -lil!). 

ft Arch. Hyg., 1904, .57:1. 



54 MEAT EXTKACTS. 

E. Kenimericli" inade a study of South American meat extracts 
and peptones, and di\ides the proteid bodies of these sul>staaces into 
three groups, depending; on their action in the presence of various per- 
centages of alcohol: (1) gelatin substances precipitated by 50 per cent 
alcohol; (2) albumoses precipitated l)y SO per cent alcohol; (3) the 
peptones remaining in solution. The extractives are also in solution 
with the peptones. The author suggests a separation basetl t>n the 
fact that the extractives and salts dialyze while tlie other boilies 
do not. 

Frentzel and Schreuer'' fed meat extracts to dogs and compared 
the results with those obtained when meat was fed. These authors 
believe that the prt>teid-free extractives of meat, to one-third of their 
total, take part in metabolism in that they produce heat and energy. 

Dr. J. Forster '^ discusses Valentine's meat juice, and con.siders it 
of no more value than Liebig's as a food — that is, it is of value as a 
condiment. 

Dr. II. Sentltner '' gives analyses of some 12 meat extracts and 
bouillon extracts. He considers the original Liebig process extract to 
be the best and cheapest. Many of the bouillons and juices are 
diluted meat extracts. 

Frentzel and Schreuer '^ have studied the calorific value of meats 
and meat meal. Dogs were used in the experiments. His results 
agree with Kubner's in showing that the calorific value of meat is 
higher than that of meat powders and extractives. 

Dr. Jung' in an article on meat extracts and peptones iliscusses the 
various constituents of these bodies and methods for separating the 
same. The author believes that large amounts of gelatin and gelatin 
hydration products are present in some extracts, being included under 
the term "proteid" since no method for separating gelatin and its 
hydration products from tlu' \'arious proteid bodies is known. 

CONCLISION. 

It is commonly assiuncd that jimtcids, gelatinoids, and the simpler 
amids have very diil'erent nutritive values, and, wliile all authorities 
would agree in assigning the liighest value to the first of these, there is 
prol)ably no small dilference of opinion as to the order in wliich the sec- 
ond and third should be rated. In considering such a riuestion, there 
should be separately taken into account relative digestibility or solu- 



oZts. physiol. Cliem., 1893, ;S:409. 

l> Bipdermann'.s Ccntrbl. Agr. Chem., 1902, J7:391. 

cZts. Biol., 1876, 72:475. 

dArch. Hyg., 1897, 6:253. 

fArA. Anat. Physiol.. 1901, p. 284. 

/Clicm. Ztg., 1900, ;.•■; : 732. 



XUTRITIVK VALUES. 55 

bility, capability of midergoint!; osmotic absorption, and oxidizabilitv 
for the production of energy. At present, no definite numerical state- 
ment of the relative nutritive values of nitrogenous bodies of these 
three classes can be made. It seeius much to be fiesired that more 
extended experiments than have so far been recorded should be nuide 
upon living animals (as far as possilile ujjoii iiiiman beings) to deter- 
mine the utilization of Ijoth ilw g(>latinoids and the simpler amids. 
The latter no doubt undei'go oxidation to some extent in the aninud 
body, and produce some energy in conseciuence. It is probably true 
of these simpler amidic substances that umch larger ([uantities than 
analysis exhibits as constituents of the food consunu'd, or than analv- 
sis detects among the residue of food rejected from the body witliout 
having undergone complete oxidation, nuiy be constantly formed 
among the earlier ])roducts of the metabolism of the jiroteids, and 
aftcrwai-ds themselves undergo lint her cliange into tlie sim])ler and 
more stable forms of carbon dioxid, water, and urea. 

In the animal body the amido acids are acted upon in two ways; 
that is, they are converted into the corrt>sponding fixed acids or car- 
bonic acid is sj)lit off, leading to the formation of Brieger's diamins, 
or it is possible for l)oth of these jirocesses to tal<e ])lace. Usually the 
albumins are converted in the alimentary trad by tlie four ])roteo- 
lytic ferments (pepsin. try])sin, erepsin, and arginase) into ]irimary 
crystalline dissociation products, namely, the amido acids, which are 
absoi'bed in tliis form. Whether a part of th(> aliiumin taken as food 
can or can not be absorbed in the form of albunioses, ]»ej)toni's, and 
peptids remains to be determined. 

Meat preparations of the sort included in this report are largely 
used l)y the sick and the young. Their use is recommended fre- 
quently by physicians who may not have taken the trouble to ascer- 
tain the true nutritive value of the j)roduct prescribed. It seems to be 
the general consensus of opini<in among scientific investigators who 
have studied this cjuestion that the food value of these meat extracts 
is rather limiteil. and althougii they are a som'ce of energy to the 
body they must not be looked ujion as re])resenting in any notable 
degree the food value of the lieef or other meat from which they are 
derived. When prejjared under the best ])ossil:)le conditions a. com- 
mercial meat extract is, of necessity, in order that it may not spoil, 
deprived of the greater part of the coagulable ])roteids, wluch con- 
stitute the chief nutritious elements of the juice. It is fair to state 
that many manufacturers make no claim as to the food value of their 
preparations, only a comparatively few making extravagant state- 
ments as to the nutritive value of these products. 

Preparations of this character are not wholly valueless in the .sick 
room, for they possess stinudating (|ualities, and in the kitclien they 



56 MEAT EXTRACTS. 

are useful on account of their flavoring properties. They are not 
however, concentrated foods, having on the contrary but' compara- 
tively little nutritive value. The meat juice prepared from fresh 
meat, in the home or hospital, by continued heating at a low tem- 
perature, is far su])crior as a food to the commercial meat extracts 
and so-called meat juices. 

o 



LbJa'03 



t^^^'^^^O^^G^EsT 




